I am currently re-reading Code Complete 2nd Edition by Steve McConnell. If you’re a developer you should not only have heard about this book, you should have read it. Preferrably more than once. This book is totally awesome and cover all the fundamental knowledge a programmer should have. Everytime you read this you will learn something new, no matter what level programmer you are.
So, if you by some unknown reason haven’t read it yet, do it now!