Synchronize Books with iTunes
Summary
OS X 10.9 (Mavericks) added an iBooks app that replaces the e-book functionality of iTunes. It is no longer obvious how you add an e-book to your iTunes library so it will be synced on your Mac.
How To
I wasted hours trying to get .ePub e-books from iBooks Mac to my iPhone until I discovered that the iBooks Mac menu item "Move Books From ITunes…" is misnamed. The menu item is really "Synchronize Books with iTunes"
Drag .ePub e-book onto the iBook icon, hit the menu command, then sync my phone via USB, and my books are where they are supposed to be.
Sloppy
iBooks in iOS 7.0.4 has a bug: Do a search that returns about 8 books. Note that there's no scroll bar in the result list, even while scrolling, and that the keyboard covers the bottom result, and you can't scroll those results into visibility. Sloppy of them.