As I've written previously, I find the iPhone Sync process to be the very devil itself. Not wanting to use the formal sync process has taught me a few tricks including how to use Dropbox for photos and how to side load ebooks.
Sideloading is the industry term for getting something onto a device in a less than approved manner. Here's what to do:
- You need an iBooks compatible resource on the public internet as a url - PDF or ePub work great and ePub is preferable
- Go to that url in Safari on your iPhone or iPad; if the url is long and complex then use TinyUrl on your machine with a real keyboard to make a tiny version of the url which will work just fine
- When Safari opens the url, select the "Open in iBooks" link in the upper right
This will load the url into iBooks and show you your new book at the top of your bookshelf.
Don't have a ebook to try this with? Here's a fascinating book on the history of PowerPoint and it is a great, great read!