Books I recommend 

Game Design

The Art of Game Design

Rules of Play

Theory of Fun for Game Design

Useful links 

Free game creation tools for beginners

So you want to make games, eh?

Creating a portfolio to get a game job

Building a strong game resume

Choosing a career in the game industry

Tips for starting out as a game artist

How to become a video game artist

Breaking into game design-I

How to get your dream job in the games industry

Game Document Templates

Game Design Document

Game Concept Document

Game Art Asset List