HOWEVER, choose your training course carefully. A puppy class would be more about socialisation than actual training, and learning to listen to you in a distracting environment. You need a small class, where dogs aren't allowed to interact with each other as they please, or you could end up with a reactive pup (or a bully). So go along without your dog (or just take him to sit next to you if he's had all his vaccinations) and observe. Are the other dogs calm? Do the trainers ensure that none of them get overwhelmed or scared?
Most important, of course, you need to judge the training methods which should be 100% positive. If they allow corrector sprays, lead corrections, and so on and so forth, walk out and don't go back
) to a class without observing one first. The class was advertised as "positive", but the methods weren't (leash jerks, etc) and the dogs were all in very close proximity to each other, which just made my dog's fear worse. I ended up dropping the class. So ask the trainer(s) if you can go and observe a class before you sign up - don't risk wasting your money on a class that will do more harm than good! (If the trainer won't allow you to go and observe, I'd be very suspicious of the situation).