Then you find content that you want. 3M has signed with lots of major publishers (3M just announced that they've cut a deal with Penguin, who pulled out of their OverDrive contract earlier this year) but they're also working with independents like Smashwords.
Once you find content, you simply click "check out" and then go on over to your My Books area (which displays your checked out books as well as lists the titles you have on hold). The book downloads to your account. And because it's all stored in the cloud, it syncs across devices. I wasn't sure what would happen when I was away from an internet connection, given that it seems to rely heavily on being connected, but I can happily report that I read a book on the flight to NYC last week, and everything worked just fine. You can also check books in really easily by tapping on the "info" icon. The "info" area also tells you how many more days you have left on your checkout, and shows your bookmarks.
A couple of things that annoy me:
1) the bookmarking function isn't the greatest. You don't seem to be able to just place a bookmark without writing a note about that bookmark. I'm thinking that the reason they made it this way is because in a perfect world your reading spot would save, and sync across your devices. In practice it doesn't always work out that way. My tablet sensitivity is high (I know I can change it, but I haven't). So sometimes I'll go from being 20% of the way through a book to 70%, just with one accidental finger swipe. Getting back to the place I was is a giant hassle then (anyone who's ever tried to "thumb" through an ebook will understand why). So I solved the problem by placing bookmarks every few pages, just in case I unexpectedly wind up losing my place. It would be nice to do that without having to write a description each time.
2) You can't use it on a kindle (though I supposed you could on a kindle fire, if you had the app) .
3) The holds list seems wonky. I've had Walking the Bible on hold for 3 weeks. Every day it tells me that it will be available in less than a day. I don't know whether they're using days measured on Jupiter, or what, but it's definitely held steady at "less than a day" like that for at least 10 Earth Days.
And really, that's just about it.
As online storage gets cheaper, it seems as if more and more programs and services will be stored online, and 3M is definitely leading the way. The nice thing about them is that they are still willing to work with independent projects (like Douglas County) and I spoke with them about possibly integrating somehow into our own project. They have written ownership clauses into the contracts as well.
I'm glad to see such an awesome project becoming successful. The library world needs more competition like this!