In the center ring we have...a Puppy?

Hello all. Thanks for the previous answers to my question. Now I am wondering WHEN should I start to teach my puppy Sammy tricks? He is 3 months old and we got him this weekend. For the rest of this week I have to be gone 4 hours a day (while husband home). Should I wait until after this time to teach him tricks or can he start trying to learn right now? Any good links for HOW I teach him? Which trick is easier to learn for this 3 month puppy? Was wondering if anyone knew or had ideas. Thanks!