Blogs

• A List Apart
• Smashing Magazine
• 43 Folders

Everything

• A List Apart - Articles
• SM's Tutorial Round Up
• Web Developer's Handbook (massive link site)
• The Web Style Guide (book)
• Getting Real - Smarter, faster way to build web apps (book)
• W3 Schools
• Research-Based Web Design & Usability Guidelines (pdf)

Other

• Hacker News

Programming

• Programming Puzzles

Note: an RSS Feed Reader, such as Google Reader, is highly recommended for blogs.