Whereabouts are you in the world?Here in the UK quite a few of the Agricultural Colleges do part time courses in dog grooming. It's worth checking your local colleges which have animal care sections and seeing what they have to offer.
If you're in the UK there are tons of Dog Grooming courses to suit all types of folk. Those who just want to learn to groom their own dog to those who want to start a business. My problem is finding one with a reasonable price attached. I have to admit to being more than just a little shocked at the price some of these people are asking. In one case over £2000. Good luck with your quest. Val