It's a great pasttime! It makes waiting in lines much more bearable :) If there's a specialty yarn store near you, that's the best place to go for advice on how to start up -- they may even offer classes! I think the easiest way to learn is from someone who already knows what they're doing... they can answer questions much more easily than a book can. If a book is the most accessible option, though, I've heard good things about Elizabeth Zimmerman and Debbie Bliss, in terms of knitting instruction.