Bathing your dog need not be a traumatic experience for your dog or for you. It isn't necessary to soak everyone and everything in the bathroom and every other room in the house!
Gather up everything you will need for the bath - easy if you keep all the bath time bits in a box. You may also want to let your dog out for a quick toilet break or bath him after a walk so he won't want to go out right after all your hard work.
You will need -
An area set aside to blow dry your dog with a hair dryer (get this set up now, before the dog is wet and wanting to do zoomies and roll around on the sofa or the lawn!) Ideally this will be an area where you can contain the dog, a grooming table is ideal but you can use another table with a rubber mat on (to stop slipping) or somewhere to tie up the dog if he is larger and likely to run off or a small room and have the dog on a slip lead. Have the dryer and brushes ready and waiting for the soggy dog to arrive.
Shampoo - nearly all dog shampoos can be watered down, this makes it easier to work into the coat and easier to rinse off afterwards. You can use either a plastic measuring jug or an empty washing up liquid bottle (which makes it easy to squirt the dilute shampoo where you need it). If your dog won't stay still in the bath then dilute the shampoo now and put it somewhere you can reach but won't get knocked over by accident - this is where the bottle is better then the jug as you can keep the top shut until needed!
Towel - keep a couple next to the bath, ready for when you need them.
Bath aid - you can get a collar which attaches to a suction cup, these are very handy as a '3rd hand' for dogs who like to jump out of the bath when you aren't watching close enough.
Waterproof apron - unless you are one of those people who like to strip down to the underwear to bath your dog??
A slip lead - you can use this to encourage the reluctant dog to accompany you into the bathroom (funny how they know when it is their turn for a wash!) and to lead your dog into the area where you are going to dry off your dog).
A rubber bath mat - your dog will be much happier if the surface he is standing on isn't slippery.
The ideal way is to have a shower over the bath or one of those shower/taps. Otherwise you might be able to bath the dog in the shower cubicle but be prepared to get wet. Alternative is to collect a couple of buckets and have these filled with warm water and jug the water onto the dog. You can have one bucket refilling while you use the other one.
Ok, you have the bath mat stuck to the bottom of the bath and the shampoo ready diluted, towels are ready and you have your apron on. Go and fetch the dog.
Place dog in bath and let him have a quick sniff about. Do not have any water in the bottom of the bath, even dogs who like water can freak at the idea of water in the bath - they can't tell how deep the water is!!
Turn on the shower and get the correct temperature, allow the dog to see the
water spray before you turn it towards the dog. Start by wetting the dogs legs
and work upwards towards the back, leaving the head and back of the neck until
last (these 2 areas often cause the dog to shake when they are wet). When you
wet these areas keep a hand on the neck as it sometimes stops the dog from
sharing the experience with you. Pointing the shower upwards will help the water
to get into the longer coats as well, just take care near the face.
When I wet the dogs face I like to tip the head down (most people pull the dogs head up). When the head is down the water will be much less likely to enter the ears or the nose - just make sure the water is poured on the dog in the direction of ears to nose.
Shampoo time. Squirt the shampoo over lots of different bits of the dog.
Start at the rear legs and work your way forwards. On short coated dogs you can
use a sponge or a zoom groom to work up a lather. On longer coated dogs you want
to treat it like a wool jumper and just squeeze the suds through the coat. Last
you wash the head. This shampoo is just to loosen up the dirt and to get the
coat properly wet. Don't be shy about washing the dogs 'bits' the dog won't
mind! You may find an old flannel or the sponge will help to loosen or wash off
any lumps of dried on pooh, at this stage you just want to let it soften up.
While you are getting your hands all over the dog, look out for any new lumps,
as you move the coat around you might see fleas jumping or rusty spots of flea
dirt.
Rinse. Turn the shower on as you did before, letting the dog see what is coming. Ideally you want to rinse off the head first to remove the chances of soap getting into the eyes, nervous dogs may need you to work your way up the chest with the water first, rinse the face and then work your way back down the top of the dog and then underneath.
Anal glands - if you know how to squeeze them and your dog needs them doing, now is the time to do it, while the dog is settled in the bath. If you don't know how or the dog doesn't need them doing then leave them alone.
Shampoo again, really work the shampoo into the coat to make sure all the dirt is out.
Rinse.
Rinse - yup, do this twice so you are sure ALL the shampoo has been washed off otherwise your dog might get a dry, itchy skin later.
Conditioner, if your dog has a long coat you may now work through the diluted conditioner. If the coat is really dry you can use it neat and/or leave it on the coat for 5-10 minutes.
Rinse again.
Wring out the dog by firmly running your hands down the dogs body, gently
squeeze the ears and paws.
Grab a towel and dry off the dog, do NOT rub the coat if it is long haired or you will end up with a matted mess. Use the towel to blot the excess water off.
With a dry towel over the dog you can lift him out of the bath (bigger dogs should have the lead put on first if you are going to let him jump out - if you are going to allow a dog to jump out you must give him a clear command to let him know when he can do this or you will end up with a dog who will leave when he is covered in shampoo!!)
You will have your dog safely contained. Have him stand on a towel, it will help
to dry off his feet quicker. Let him look at the dryer, if he has never heard it
before I find it helps if you imitate the sound first, then turn on the dryer.
Make sure the dryer is pointing away from the dog when you turn it on. Start at
arms length and slowly move the dryer closer to the dog, again starting low on
the dog (as you did with the shower). With short coated dogs you can just move
the hair around (where the dryer is pointed to) with your spare hand. Long
coated dogs should be dried using a brush to move the coat apart so you can dry
from the roots (same idea as drying your own hair).
Some dogs will object to having their faces blow dried, unless you are going to be trimming the dog right away it isn't of great importance if you leave the face damp. Do take care not to blow air into the dogs ears or eyes as this can cause irritation, especially the eyes which may need vet attention if you aren't careful! Some dogs do seem to like to try to stare at the warm air flow.
While you have the dryer on, use this opportunity to look at the dogs skin. You might find new lumps and bumps, warts or the occasional flea. As the coat dries you may also find small knots or mats in the fur, especially in the hard to reach areas that can get missed on the regular grooming sessions.

Time to now go over the dog. Short coated dogs can have a spray with a conditioning spray and a polish with a piece of velvet to give the coat added shine. Long coated dogs can also have the conditioning spray, lift the coat up and then use a comb to check you have got out all the tangles.
You can now give your dog lots of praise and a treat or two and let him go off to have a good shake and roll around on the carpet. Your dog may need to go out for a pee, just watch he doesn't try to roll in the muck outside or you will be repeating the bath routine again!
There are far to may types of shampoo to discuss here, some are designed to
enhance the coat colour, some are conditioning, some are made to treat various
skin problems, some are insecticidal and some others are just to make your dog
smell nice. So how do you choose which shampoo to use?
Look at your dogs skin - are there any problems? If you have been sold a special shampoo by your vet and the instructions say to leave on for 10 minutes then you should take a clock or watch into the bathroom and time how long. Why spend a fortune on these shampoos and then not follow instructions? Surprising how many people never do. Also beware that some require you to wear protective gloves.
If your dog has eczema there is a shampoo called 'eczema rid' with a picture of a Westie on the front, this may help as might a coal tar/sulphur shampoo. Some find that tea tree shampoos or evening primrose shampoo help. It can be trial and error finding the best shampoo that works on your dog. If the skin is bad, don't waste time trying shampoos, go see a vet especially if the skin maybe infected.
Fleas? Vetzyme JDS shampoo is one of the best BUT it only kills fleas that are on the dog, any that are in the environment will be able to hop on again later. Treat the dog with a spray, flea collar or back of the neck drops and also treat your house with a household spray to kill of any flea eggs. This shampoo is the choice of a lot of show people who want to maintain the texture of the coat.
Does the coat need treatment? If the colour is a bit sun bleached try a colour enhancing shampoo and a leave in conditioner with sunscreen to prevent further damage. If the coat is dry look for conditioning shampoos and separate conditioners.
Fine coat texture, e.g. a Yorkie, look for a shampoo that is clarifying and will not weigh down the hair, these breeds if handled often are prone to getting greasy coats. However the longer coats may still benefit from a light conditioner or a spray in conditioner after the bath when you dry the coat. Vitacoat Yorksheen cleanser is specially made for this type of coat.
Smelly dog? First check the dogs ears, mouth and feet. Infections here can go unnoticed and cause a dog to smell. Skin can get yeast infections which can also cause a dog to be smelly - a vet check might be in order if a good bath has had little effect. Some breeds are also known to have more of an odour about them. Highly scented shampoos and perfumes can dry the skin and cause other problems. Also consider if the anal glands need emptying.
If your dog has no problems then just go for a quality shampoo that you like the smell of.
Some people also use baby shampoo on their dogs as it is a mild, tearless product.
Be aware that human shampoo has a different pH to dog shampoo because dogs skin is different to ours. Human shampoo can dry out a dogs skin to much, though some dogs have no problems with this.
You can also buy 'dry' shampoos, these will be a mousse or liquid that is worked into the coat and do not need rinsing out. These are best kept to cleaning up small parts of the dog, not to be used for a replacement to 'bath time'.
The simple answer is when he is dirty or smelly! Wire coated breeds are best not bathed very often as they will loose some texture to the coat, not important in the pet dog. The important thing is if you are wanting to bath your dog often, pick a good quality, mild shampoo, rinse it out well and keep a check on the dogs skin. Regular bathing will remove the dogs natural oils/weather proofing but for those dogs who live indoors this is not a problem.