Go to SFPL overdrive library, look for books you want to read. The catalog is not as quite nice - you might need to request a hold for popular books, which I did yesterday and received updates this morning that it is available now.
Like a normal Kindle book, you can sync wirelessly to any device from here. I chose my iPad but am now at work and can't read it here - so I launched the Android app and Kindle cloud reader, confirmed that I can read the book in any of the devices. (What is the pulldown for, if I can pull from them on any device anyway?)
This is really nice.
The SFPL account also gives access to O'Reilly Safari bookshelf (not all, but most of the catalog). Something you should really have if you live in the city :)