There are tutorials all over the internet for polymer clay but here are some of my favorite choices.
Glass Attic	Online, all-in-one-place "encyclopedia" of polymer clay information. A superb resource, almost anything can be found there. Input from many polymer clay artists.
Skinner Blend	The Skinner Blend has become one of the best tools we have for shading our work with Polymer Clay!
Mokume Gane	Mokume Gane (pronounced moe-koo-may-GAHN-ay) is the Japanese term for "woodgrained metal". In polymer clay terms, it is a method of stacking, constructing, or otherwise layering polymer clay to achieve a myriad of interesting and beautiful designs that you can use for any application.
Mokume Gane with Fiesta Inks	A tutorial on mokume gane using fiesta inks instead of different colored clays.
Desiree's How-To	There are 5 How-To's focused on tools; 8 How-To's focused on creative projects.
Polymer Clay Express	Polymer clay mini-lessons, instructions, projects and tutorials
Polymer Clay Central	A wonderful place to spend an hour or two, so much to learn, see and do.
Sunni's Tutorial Links	There are a myriad of links here, so many to choose from.
Polyform Projects	Home of Sculpey and lots of projects on hand.