The best way so far that I’ve found to keep track of my increasingly massive classroom library is using booksource.com‘s Classroom Organizer.
It’s really easy to create an account and start organizing your library and checking books out to students. It is really helpful to have a second computer in the room (other than mine) to do this check out process.
I’m still working on typing in ISBN numbers as kids check out books because I wanted to get it started right away. A lot of kids are “getting it” which is good.
I’m hoping they have an iPad compatible scanning app, but I haven’t tried that yet.