Great resources above.

Just wanted to add Here Comes Science DVD by They Might Be Giants (warning, you should skip it if your family disapproves of evolution discussions) and Daniel Tiger's Neighborhood on PBS and Netflix.

Daniel Tiger has really been wonderful for helping my son deal with emotional growth, learning social skills, and even potty training. It is just a sweet natured show that my son really responds to well. I found he has been responding even more to it at he gets closer to 3.