As someone else said, the AAP recommends no TV until age 2. After that, it is supposed to be 30 minutes for every year of the child's age. Personally, I think that guideline is a little much.
My first child did not watch any TV until 2ish (except for a long trip or two in the car and even then we waited until the end of the trip when all the tricks in the bag were used up). She loves to read books and knows how to play independently. I do let her watch certain shows now, but it is usually an incentive she earns.
I'm glad that I had a no TV rule for my first and have done the same with my second. In fact, the rare time that the TV has been on, my baby will look for a second and then continues to play.
They'll have plenty of time for TV and movies when they're older.