A List Apart
In depth articles on modern web topics.
Interesting blog on current techniques and tools
Pro DNS and BIND eBook
Very in-depth look at DNS terminology and practices.
Name says it all.
Learn to Code Advanced HTML & CSS
Really thorough online guide that details many higher level topics including jQuery, animations and feature support.
Mosaic mashup of a variety of websites, css techniques and assorted other goodies.
Sentdex on Youtube
Video tutorials on Twitter Streaming, MongoDB, Python and more.
Probably the best tool out there for editing, testing and playing with code.
All of your programming questions answered, if you know what to search for.
Resources, interesting articles & freebies. They do a great email newsletter too.
Another web design showcase reel. Mostly minimalistic/retro in style.
Color scheme designer and previewer.
CSS Font Stack
Groups similar fonts to prevent unwanted substitution as a result of browser fallback.