well the first choice of learning materials is obvious..
view the tutorials in the help files.

second choice, wich is also kind of obvious, could be www.simplymaya.com - buy some points and start downloading videos They are great!

third choice could be www.learning-maya.com for tutorials of all kinds.

I would begin with modelling tutorials and go for simple stuff that interest you.

Remember to have fun while you explore!

good luck