Q: Is there an easy way to share an ebook with my wife? I purchased it with my iPad and would like to share the book with her so that she can read it on her iPad. Can she log in under my account to log in as we do for apps we share?
A: The short answer is yes, that’s pretty much it. iBooks are handled in basically the same manner as other types of iTunes-purchased content, meaning that you can store and use iBooks from a given iTunes Store account on up to five iOS devices, and can store iBooks from up to five different iTunes Store accounts on a single device.
There are a couple of important caveats to be aware of when doing this, however, particularly if your wife has her own iTunes Store account that she uses to purchase content on her iPad. While you can store iBooks and other content from multiple iTunes Store accounts, you can only download previously purchased content from a single iTunes Store account at a time, with a 90-day waiting period required to switch accounts.
This applies if your wife has downloaded any previously purchased items from her own iTunes Store accounts—including not only books but also music, movies or TV shows—or if she has automatic downloads or iTunes Match enabled under Settings, iTunes & App Stores. In this case, she may either be unable to download the iBook directly from your iTunes Store account, or if she does do so she will have to wait 90 days before she can switch back to her own iTunes Store account for any of those features. Note that this would not affect her ability to purchase new content with her own iTunes Store account—only downloading previous purchases, automatic downloads and iTunes Match are affected by the 90-day restriction.
If this is the case, the easiest way to work around it is to simply load the iBook on via iTunes. This does not affect the iTunes Store account that is configured on her device, and also transfers any necessary iTunes Store authorization as part of the iTunes sync process. If you use the same iTunes library, this is pretty trivial to do—just sync it on as you normally would for your own iPad. If you each have separate iTunes libraries, however, you’ll need to transfer the iBook over to her library either by copying the file manually or using the Transfer Purchases feature in iTunes. In either case, you will need to manually authorize her computer for your iTunes Store account by using the Authorize This Computer option found on the Store menu in iTunes. This will not affect any iTunes in the Cloud or iTunes Match settings, however, as you’re not signing into your account—merely authorizing the computer for an additional one.