As educators, we spend our time creating and sourcing relevant content. Some of us even go so far as to write our own publications. Here is a fantastic website that allows you to publish your own work and then have it made available on numerous sites such as:
OverDrive - this way your students (if your school has an OverDrive account) can take your book out of the school digital library
iBooks
Barnes&Noble
kobo

Now more than ever, it is possible to write and publish your own work. Visit: SmashWords