Family Fun magazine always has lots of fun activities.

Toddler Games & Activities | Games by Age | FamilyFun

I like "The Preschooler's Busy Book" and they make a version for toddlers. Here's a link . . .

Amazon.com: The Toddler's Busy Book: 365 Fun, Creative Games and Activities to Keep Your 1-1/2 - 3 Year Old Busy (9781856355391): Trish Kuffner: Books

I've also gotten good ideas out of "365 Outdoor Activities You Can Do With Your Child" by Steve & Ruth Bennett although that includes many activities that would be for older kids.

Best of luck!

__________________
Proud Mommy of Three Supercool Kiddos!

Your son is at a really fun age. I would suggest you work a variety of things into your day, some puzzles, some colouring, outdoor time for sure. He is plenty old enough to be running on uneven ground like trails and parks. He can go on a "big boy" swing on his belly. Twist it up (just a bit the first few times) and when he gets comfortable he will splay out his arms and legs like a helicopter. Play tag on a baseball diamond. Teach him how to climb up and down and jump off the bleachers. I am a believer in parents not entertaining their children constantly, instead I think they should let them just play on their own sometimes with you nearby. There are some great story shows, reading shows etc. on TV. I run a daycare and the TV is only on when I am preparing a snack or a meal but I let them watch Super Y (or Wye because the character's name is Wyatt). It is engaging, active at times, tells a fairy tale story and includes problem solving, all the while teaching reading. Another great show, and you can get them from your library, is Magic School Bus. If you do a little of each of these things every day (outdoor activity is a must) and make your child healthy food you will be setting great patterns.

The kicker is....you need to do it with them, not just stand by. You get him going and then be there to cheer him on when he gets going himself.

Good luck