What is the age range and what kind of show? Teens and younger, I would go with Yugioh and Pokemon, although I don't know much about them. I would go with Magic for 16+ and usually the newer sets are what you want. Return to Ravnica, Avacyn Restored, and Core Set 2013 are the newer ones. Packs are usually like $4 and you can find boxes (36 packs) around $100.
Sports Card Album: http://sportscardalbum.com/u/meetjsquared/a/fsft
Full Want List: http://bit.ly/1cWBzxc
Main Wants: Rodgers 2012 5* MVP Auto, Fitz SPA RPA, Megatron NT RPA, AP NT RPA