As eejack pointed out, there are big dangers in reading the Wrong Manuals (or at least, in reading them first).

The single book that taught me the most was Structure and Interpretation of Computer Programs. I can only encourage every programmer to work through this book. Especially those programmers that are self-trained (like me) will profit from it. It will give you a strong foundation to build on.

Christian Lemburg
Brainbench MVP for Perl
http://www.brainbench.com