Getting Started With Arduino
A very basic book to get you started with Arduino if you have absolutely no clue about electricity or electronics and how they work. A little too basic for me, but it does contain some interesting project ideas.
A more advanced book. Packed full of projects for all different types of applications using all sorts of strange and wonderful electronic components. Learning by example generates the most creative ideas (for me at least), so having a compilation of projects like this could spur things off in a number of directions.