I'd noticed my chef's knife was seeming a little dull, and was thinking I should probably sharpen it when I stumbled across this excellent eGullet post about Knife Maintenance and Sharpening. It's so in-depth that I didn't do more than skim it yet, but looks like a great resource for sharpening. Now to find the time to read the whole thing before I sit down with my stone and get my knife back to proper sharpness.