This is probably no help, but here's my opinion, just for fun. I have never watched the Baby Einstein videos.. so I can't comment on them specifically. BUT, just remember that once you introduce TV to your little one, it can be very addictive to them. My son never watched anything on t.v. until he was about one.. even then he didn't have a lot of interest. I didn't let him watch any t.v. programming, just started out with Winnie the Pooh (the original). Eventually, he would be still enough to watch more than 2 minutes of it. But when he became ill w/stomach bug (rotovirus I think) it was a Godsend. We could lie on the sofa together and the music is so soothing, and the movement is slow (not the quick images that so much tv has that adds to attention deficit issues, imho), and he would doze off. He then became more attached to the characters and they were soothing on their own (stuffed animals). He really didn't begin to enjoy watching stuff until he was closer to 2. Around 2 1/2 he began watching a cartoon called Franklin (about a little turtle and his woodland friends) and of course, grew from there (he is now almost 10). (and I still love Franklin!)
I would say to stick with toys and musical books and things like that. He is not old enough to be watching ANYTHING on tv. He needs to learn through tactile play... (touching things, not watching images)
It can be hard to "keep them entertained", especially if you are home all day alone with him. So try to DO more (not try harder at the same stuff-YOU'll be bored)... take a walk around the block, or go to the mall and take a walk from end to end.. get a pretzel while you're there and let him smell the salt on it, walk around in your backyard and talk about the flowers and butterflies, if you live near the beach... go there! You don't have to pitch a blanket or anything.. just park and take a walk for a little ways on the sand (or boardwalk) and then leave. The ocean sounds and smells will stimulate his brain (and maybe relax yours too!) You could even walk out into the garage during a rainstorm and let him hear it/smell it (it IS different)...
I stayed inside a lot b/c I was new to the breastfeeding thing and I was nervous about it, but there are SO many accommodations for moms now, and you don't have to go very far to just get out of the house. Just the new sights, sounds, smells will tire out baby, and it'll be more peaceful for you both while you're out and after you are home.
I would try to hold off on using the TV for a while longer... especially since you have a boy. They are more prone to NOT sitting still very long anyway.. and while it might seem like you are teaching him to do just that, actually, his eyes are watching quickly moving images that teach his brain to crave that visual stimulation. Get leapfrog interactive toys instead.
Babies get plenty of stimulation just by exploring their natural world! Try to imagine if you were from another planet and just got to earth 3 months and 3 weeks ago... what might you find interesting?? (The dirt, the wind, shadows, cats/dogs, flowers, sounds outside, water, sand, grass, reflections, etc)