If you want to add books you don’t purchase from Apple into your iBooks library, you have two main methods: sync with iTunes or sync with the iBooks app in Mavericks. They’re both not the most intuitive things in the world though, so if you’re sick of bothering with them, Cult of Mac points out that sending an email with an Epub attachment does the job. Read more…
More:
Skip iTunes and Add Your Own Books to iBooks with an Email