My favorite clay crafting reference is The Polymer Clay Artist's Guide by Marie Segal.
If you are a newbie to polymer clay crafting, the book has very clear explanations about the materials used as well as the different types of tools needed. It also simply explains some very basic techniques to get you started with making beads or even jewelry pieces.
And then the real fun begins! There are pages and pages filled with stunning photos and step by step tutorials for creating different effects and designs that you would never imagine possible. I was wowed by the directory of effects ranging from textures and printing to caning and mosaic.
At the end of each section are photographic examples of how the 50+ featured polymer clay artists incorporated the effects into their own real world creations.
Every image in this book will get your creative juices flowing and there are enough different techniques described that as a casual crafter you may never get through them all, but won't it be fun to try?