At 11 months he has a very short attention span 1-2 minutes, at most. This is why Seasme Street was structured the way it was. I haven't watched it in many years. But they always did very short snipits so the lessons would hold a child's attention.
You can surely do things like here is your juice in a red cup, or your lunch is on a plue plate and the plate is round. This teaches color and shape. But peek-a-boo is a fun game, it teaches that mommy can 'disappear' for a few seconds and come back. You can see if he will roll a ball back to you but he may be a little young for that one. You can sing "Head Shoulders Knees and Toes, touching his body parts as he hears the word.
http://www.youtube.com/watch?v=d8FwBSITW-4
Here's another one:
http://www.youtube.com/watch?v=71hqRT9U0wg
When you take him outside talk to him about the soft green grass, the pretty flowers, the furry dog.
He's really little yet and his brain is absorbing everything. But he will learn best if you just talk and be discriptive. He may not respond or say it back to you but he will learn.
Mostly enjoy him, before you know it he will be off to Kindergarten, then all of sudden he going to prom and graduating. My baby is 21 and it is hard to believe.