Professional Development Handbook/Ladder and SWEBOK
Probably most of the people who have ever read "Code Complete" or its second edition or any other book by Steve McConnell have browsed systematically through Construx’s web site. One of the most interesting pieces of information for me is their "Professional Development Handbook" and "Professional Development Ladder". Sure, Microsoft has its internal equivalent documents, but nevertheless it’s very educational for more complete world-view to understand what’s happening in other software companies or towards what industry is moving in general. I usually try to reread these documents every three months or so to understand how my personal thinking has changed ;-)
One other thing which has been in my TODO-list for long time now is to read through the latest version of SWEBOK. SWEBOK stands for "Software Engineering Body of Knowledge". Based on my personal experience when talking with different people about SWEBOK it seems to be one of these things with what professionals either agree with or violently disagree. Your mileage may vary of course.