Puppy School?

Hello,

I was wondering if 12 weeks is too young to bring Shelby to puppy training school? She pretty much has been housebroken. She is very smart and so far has gotten the routine at home. However, Kris and I want to train her some more. We would like to take her to puppy school.

So...1) is she too young or perfect age?
2) Can anyone recommend a good puppy school/trainer in Bergen County?

Thanks,
Antonia & Kris
puppy Shelby