You can do so many things with him... don't force the learning on him, though...
Get out pots and pans, turn them upside down,, and give him a wooden spoon.... you each take a wooden spoon and start hitting the bottoms of the different pots... take turns.... you can also comment on how the sounds are different on different pots....
Take plastic containers and stack them up for him.... encourage him to knock them down... he is then learning "cause and effect".....
sing some of the different nursery songs with him... clapping his hands together as you sing them..... "dance" with him as you sing....he learns music and rhythm...
One of the "games" we used to play was "row, row"... sit him on your lap (as you sit in a chair), facing you... take his hands, and sing "row, row, row your boat" to him as you "row" him back and forth....
give him a horsey ride on your lap as you recite "Gallopy trot to the blacksmith shop to shoe the horse, shoe the mare, but let the wee little colt go bare" .... jounce your legs up and down gently while you hold him, like he is riding a horse.....
Any of these activities babies love... they love the interaction with you....
So many things you can do just throughout the day.....
Play peek a boo... they love this!