Note: I stay home so preschool was mostly done by me or my mom

We've had a subscription to starfall.com for years. They loved playing the videos and mimicking the movement songs. These are things they would be getting in a preschool/daycare. You can watch "Head-Shoulders-Knees and Toes" and Wheels on the bus without a subscription. They help with gross motor skills, body part identification and vocabulary. If you like it I suggest subscribing. They also have a "radio" function that plays basic nursery rhymes and kids songs to help with vocabulary.

http://more2.starfall.com/m/level-k/body-motion-demo/load.htm. Play it on the biggest screen you have and dance/sing with him.

You may also want to check into abcmouse.com it costs a bit more but is pretty thorough and you select a level that fits your child.

Also check out the free programs at your local library for toddlers. You will get a chance to interact with other mothers and observe them and the children while playing and learning. The system in NOVA has some great free puppet shows, story times and sing alongs for toddlers.