Links are good.

These are some of the sites I visit on a relatively regular basis.

Macs

Accelerate Your Mac - Mac hardware info mountain
DealMac - Keeps track of cheap Mac stuff
i use this - Popular Mac software
Mac Update - List of new software...addicting
Macworld - Mac news
Open Source Mac - Nice list of free Mac software
VersionTracker - Another list of new software

Reference

CSS Properties - Possible values and examples
HTML Tags - Examples, attributes, etc.
Special Characters - A complete list

Icons

FamFamFam - A slew of open source icons
Icon Archive - Great icons for Win, Mac & Linux
iConvert - Best online icon converter

Tools

AnyBrowser - View web pages in different browser sizes
BrowserShots - View your site in different browsers
Malelove - Dummy text generator
Postable - Make code post-friendly
Winmaildat.com - Winmail.dat extractor

Other

Ars Technica - Great tech site
Boing Boing - There's always something interesting here
Digg - Great news site
SlashDot - Geeky news and discussion
The Register - Euro tech news site with attitude