Would Overdrive suit your needs? All members of the San Francisco public library can download and read books for free for 21 days at a time. They have a large collection of Young Adult titles. Books can be read on PCs or on eReader devices
I don't know if the Oakland PL has implemented access to Overdrive books, but it sounds like it might be a simple solution for you.
http://sfpl.lib.overdrive.com/