Loading Books to an iPad Without iTunes
Dropping files into iTunes, connecting your iPad to your computer and syncing is one way to get e-books onto the device, but it's by far not the only one. If you're tired of fiddling with the USB cable all the time, there are several alternatives you can use to get your e-books where you want them with a minimum of fuss. All methods do, however, have the same file type requirement as syncing through iTunes. If your e-books are not in the ePub, PDF or iBooks' own native format, you won't be able to open them using iBooks.
1 Getting What You Paid For
One of the main ways of getting books for your iPad is to buy them from the iBooks store, either through the iBooks app or through iTunes on your computer. If you've done the latter, you don't need to sync them from there. Instead, open the iBooks app, tap "Books" and then tap "Purchased Books." All the books you've ever bought from the iBooks store using the Apple ID you're currently signed in to will be there, with ones currently not on your iPad marked with a cloud symbol. To download a book, all you need to do is tap it.
2 Download at Will
If the book you want to put on your iPad can be downloaded from a website, you don't need to go through your computer. Just open the website and then tap the download link for the e-book; once the download is complete, you'll see a link labeled "Open in iBooks." When you tap it, the iBooks app launches automatically and the book appears in it, opening to the first page. If there are more books you want to download, you will need to repeat the process for each of them.
3 You've Got Mail
When you receive e-books as email attachments, the process is quite similar -- download the attachment and you'll be prompted to open it in iBooks once the download is complete. This means that to get an e-book from your computer to your iPad all you have to do is email it to yourself. How convenient this is, of course, depends on how many e-books you need to move and how large they are.
4 Your Library in the Cloud
With a bit of work, you can turn a cloud storage service such as Box, Dropbox, SkyDrive or Google Drive into a library. Upload all the e-books to your cloud storage account and then, if you haven't already, install that service's app on your iPad. Through the app you can access all files on your account, including your e-books; download an e-book and you'll be prompted to open it in iBooks. This method can be particularly useful if you have more than one device on which you want to access the e-books, since you'll only need to upload them from your computer once.