I'm glad that you are so aware of this.
Yes, it's true that puppies are supposed to have all their shots before meeting other dogs. I talked to my vet about and about all the associated risks. We came to the conclusion that this imprint period is so important for a dogs development that the socialization is more important. HOWEVER, if you do live in a high risk area it is best to stick to puppy schools. Ask your vet if he/she knows about any that are close to you. That way your dog can socialize in a safe enviroment.
We did allow all our puppies to meet dogs that had all their shots up to date. There is a small risk involved of course, but I figured that it is very minimal and therefore more important to get the puppy to interact with other dogs. Obviously I didn't take them to the dog park until 2 weeks after they had all their shots.
The more interaction they have the better. The puppy I currently train was very confident and dominant and she might have turned into a bully without proper socialization.
Good luck, all the best and let us know how you get on