Guides, Tutorials, and Validators
Accessibility Checker
Alertbox: Current Issues in Web Usability
Bare Bones Guide to HTML
Beginner's Guide to HTML
HTML Validation Service
HTML 3.2
HyperText Markup Language
Library of Congress Internet Resources
Net Mechanic
Ten-Minute Guide to HTML
Yale C/AIM Web Style Guide

References and Standards
HTML 3.2
HTML 4.0

Other items of interest
Center for Applied Special Technology
Computer Incident Advisory Capability (CIAC)
Cornell University: I.T. Rights and Responsibilities
Princeton University: I.T. Resources and Internet Access