Alternatively, you can also use SugarSync. It's similar to Dropbox, but you get 5GB free, with 500MB for people who sign up using this link:
https://www.sugarsync.com/referral?rf=eg3qan4yhp4ry. Remember to install the system manager as that's the key to the bonus.
You may even want to use both Dropbox and SugarSync--one for e-books and one for video or music.