First, look up a grooming forum in your country. They will provide SO much help and information.
Second, if you're serious about becoming a dog groomer, apply at your local pet chains and grooming salons to be a bather. It's not the prettiest or fun job. Between anal glands, the hair, (oh my the hair! In your clothes, food, eyes!) bites, "fighting" to control a bigger sized not-so-thrilled dog, quite a few people that get hired as bathers quit after awhile, deciding it was not what they imagined it to be. You may very well like it though! A lot of people do, and it's really not that bad. Just keep in mind it's not a sit down office job, and it's not "playing with dogs all day"
Might save you some $ in courses if it turns out it's not what you wanted.
Some groomers will even teach you after you've been bathing for awhile. You can ask upfront.