Every case is different and so is every hospital. I've always been told that no one knows me because I'm rarely in there, but after the first time I was in (when I was 16), I seem to have been in almost every summer after that. I stayed two weeks the first time, the second time I decided to stay in for a week, and then go home, but I wound up on IV's for over a month! So the last time I went in, I just stayed the full two weeks, and was out after that. When I did my IV's at home, it was up to me to do everything on my own. I had to wake up and stay up late to administer them, and after the first few days, I got really tired of it, and I personally thought that the hospital did things more efficiently. Plus I was going to work the weeks I was home, and I don't think that helped much.
But anyway, like everyone else said, when you're in there, they do all the nebs about 4 times a day, IV meds, chest pt, and physical therapy on some days. There are some people that try to get you to join in fun activities, but at my hospital, we are bound to our rooms and can't leave unless it's for PFT's or X-rays. After the first week they check your PFTs and X-rays to see if you've improved, and the second week they do the same thing. If you're pretty much better, they let you go.