I have been reading my Learning Maya: Character Animation & Rigging Book whilst stuck in traffic going to work and it has been very enlightening. I am nearly half way through and although I haven't applied the knowledge yet (too busy on my project) it is written in a way that makes it easy to absorb and understand.
Yes, it can seem complicated to the complete novice but if you have some knowledge of rigging and animation it helps. I found Maya quite complicated to start with but with the right learning materials and persistence it starts to sink in and make sense and become easy to become at one with!
So! I would recommend the book to someone wanting to learn the techniques, I like the MEL expressions bit - powerful, but for the seasoned rigger who wants advanced techniques get the book from Sybex 'Maya Character Animation' out in December - it looks good!
Well, that's my little book review, one other thing I would say is that this book is a bit pricey at £60 or so although you can get it from Graphics Domain a bit cheaper. I would give it 8 out of 10.
Tickety boo and ta ta for a bit...