There are a couple of lessons on the Wholenote web site that pertain to arpeggios and scales that I found really helpful, especially if you want to play blues or jazz. They may still help you out in other styles, though.
Go to http://www.wholenote.com/ and look under the jazz heading for the CAGED system. They are positions for scales and arpeggios that don't require outragous hand flexability- they're pretty comfortable and very versatile.

Michael