Definitely do the puppy school/obedience training, because they will give you some good ideas too.

Also, invest in some Kong type toys, that you stuff with food, the dog then has to work quite hard to get it out, same goes for marrow bones. I sometimes stuff the empty marrow bone with other goodies and little smear of peanut butter/cream cheese/vegemite on the outside makes it interesting and gets them started. You can give your puppy their own sandpit and bury things for them to find, also hanging a toy from a rope where it will swing back and forth can be quite entertaining for them.