Fingers can be tricky to rig, but there are several ways to make the setup easier to handle, without having to spend too much time making adjustments or compensating for orientation issues (6 min 47sec). This video is only a small portion of longer lesson, developed for one of my rigging guides (Rigging Techniques).
If you're looking for more tips and lessons, have a look at my growing list of rigging guides, developed for iBooks and for other ebook readers...
iBooks - http://itunes.apple.com/us/artist/jeremy-a.-parrish/id507724058?mt=11