Just make sure the puppy feels confident with you, then take him where you want. I am not a fan of dog parks, doggy daycare or puppy kindergarten if they allow puppies to romp and play with each other.
I am picky who offers my dogs treats or pets them. If a harassed mother with 3-4 kids in tow comes up and some of the kids reach to pet the puppy, I will say no. If a polite, calm parent or child comes up and asks permission to pet the puppy, I will usually say yes, or I will qualify it: one at a time, or he has to sit.
Socialization is an opportunity for you to set your puppy up for good experiences. Watch your pup, and if he seems to have had enough, either backing away or getting hyper, then tone it down, go home for today. Like any type of training, keep it light, keep it fun, and quit when the puppy still wants more.
Heidi Ho, Odie
Joy-Joy, Bear Cub, Hepsi-Pepsi
Cujo2, Karma Chameleon
Ramona the Pest, Kojak -- who loves you baby?
Tiny Tinnie, Susie's Uzzi, Kaiah -- The Baby Monster.