I just got a new hard drive and I want to sync all my iPad stuff back into my iTunes but it's just asking to erase the iPad. I just want all my books and stuff to be back in my iTunes.
As I referred to in the comment:
- Right/(Control)-Click on iOS device in sidebar of iTunes.
- Select Transfer Purchases
This copies over everything you purchased using the iTMS, App store, and iBooks.
For all content you put on the device that you purchased/received elsewhere, the process is a bit more complicated. Here are some suggestions:
- Right/(Control)-Click on iOS device in sidebar of iTunes and select Backup. These at least gives you a place you can quickly fall back on.
- If the computer in-question is a Mac, I can't recommend Podworks enough.
- If Windows... well I haven't tried any, but found this thread on SuperUser.
Hope this is enough to get you going. Best of luck!