Yea, Digital Tutors is a good place to start, I've used several of their products for Max. http://www.digitaltutors.com/software/Maya-Rigging-tutorials
I am looking forward seeing that =D For rigging.. i learnt alot from just experimenting myself and breaking apart other peoples rigs i downloaded. I also had some help from a friend i used to work with and digital tutors maya rigging stuff is solid (i haven't actually finished one of their tutorials tho :p )
I'm working on a free indepth tutorial series on how to create the maya modular rigging tools from my site with python. Should be out really, really soon :)
Digital Tutors covers a lot of the basic/intermediate stuff for most 3D apps. "The Art of Rigging" books seem to be popular for the more advanced stuff.