ImTOO iPad PDF Transfer lets you manage your iPad book library. The application lets you both transfer the books that you have on your iPad to your Mac, and put new content on the iPad without syncing with iTunes. There are tons of users who can't stand the syncing process, and this tool gives them an easier way to put books on their iPads. The app works both with the iPad 1 and 2, and it should also work with other iOS devices.
The application's main window shows some details about your iPad, such as device type, capacity, iOS version, serial number and format. There is also a graph that shows the space used and the space free, and how much of that space is used by audio, video, photos and books.
On the left pane, below your device, you will see a button that reads "Books". If you click on that, the right pane will list all the books that are stored on your iPad. It will make a distinction between ePub and PDF books, and you can download and upload both from the buttons at the bottom of the screen.
In short, this app works nicely. It detected all the books that I had on my iPad, and it let me upload books without any problems.