Code Complete by Steve McConnell
Clean Code by Robert Martin
Working Effectively with Legacy Code by Michael C. Feathers
Design Patterns by Gamma, Helm, Johnson, and Vissides
The Mythical Man-Month by Frederick P. Brooks, Jr.
Linux Pocket Guide by Daniel J. Barrett
The Linux Programming Interface by Michael Kerrisk
This is by no means the perfect list for everyone, but as a web developer I find myself coming back to these over and over. It may be noticeable that many of these seemed geared towards software development rather than web. It might be my ambition or just a need to bring more order to the chaos that is the web. I want my work to be of quality and my try to reflect that in my reading.