Went to a nice course and got loads of good ideas. Here are some: bounce the baby (gebtly) on a swiss ball, singing: Row, row, row the boat...or anything else. My dd loves bouncing!
Paint with finger colours in the kitchen or somewhere easy to clean, great fun!
Sing nursery rhymes and play one-on-one with him: Pat a cake, etc
Read books with him, start with big pictures and then small stories. If you want them to take an interest in book, you have to start them early!
Take pictures of your family, one by one and put them in a box, go through these pictures and talk about who you see and say there names, tell your LO what they're doing or wearing. You will enhance his vocab.
Having the TV on all the while is just sad because there are so many good things you can do and he loves your voice more than anything else he hears. Plus: children learn to speak less clear and have less vocab if there's always a TV on in the background.
Also, you can take a picture of an orange or a banana, then next to that place the actual fruit. It will help your ds to recognize the same thing in 2D, 3D. Good fun!