On a system with enough Personal Books that the list is longer than what shows in the pane when Tools/Personal Books is executed:
1. Select Tools/Personal Books.
2. Click on Add book
At this point it should scroll to the bottom where it brought up the new book pane. If one was unfamiliar with this interface they would have no idea that a pane has been brought up for them to start entering information in!
By scrolling to the bottom where the new pane is behavior would be the same as WIndows version
OS X Verbum 6.6 SR-3.