Off-Topic :
Fairfax Underground
Welcome to Fairfax Underground, a project site designed to improve communication among residents of Fairfax County, VA. Feel free to post anything Northern Virginia residents would find interesting.
If you really have to design your pages for a specific resolution, it's safe to go with 1024x768 anymore, but if you want to include people with really old computers still using CRT monitors etc, stick with 800x600. (I think the conventional wisdom is that about 5 to 7% are still using 800x600)
However, you should be using relative DIVs and percentage widths to create a page that will collapse and expand based on the visitor's screen resolution.
1024x768 is how it should be designed, but you should also have the site centered and scalable so that it will auto-adjust for various resolutions. Don't make it fixed.