Q: How can I share JUST my Books with my other devices?

Hi spiderwa,

Thanks for visiting Apple Support Communities.

If you have past iBookstore purchases, you can download them to your devices using the steps in this article:

Downloading past purchases from the App Store, iBookstore, and iTunes Store

http://support.apple.com/kb/HT2519

For future purchases, you can turn on Automatic Downloads to download purchases automatically to multiple devices:

iTunes Store: How to enable Automatic Downloads

http://support.apple.com/kb/HT4539

Cheers,

Jeremy