Syncing books on multiple computers

Every time I try to work through syncing my ipad on both my laptop and my wifes laptop I end up walking away in total frustration.

Seriously, could they have made this thing more confusing?

I use Azul for video's which is a dream come true, I simply plug the iPad into whichever computer I want, add a video to the apps list, and boom it syncs. Beats the hell outta Apples "total control" way of syncing.

Does anyone know how I can simple add a book to my list of books from multiple computers?
Every time I try to tick "Sync Books" it tells me it will erase all of my media on the device.

Otherwise, does anyone know of an app like Azul but for books?

Thanks!

 

Nevermind, come to find that Kindle app actually catalogues PDFs in the same manner as Azul so all is well again.