I know that not everybody has the same screen resolution so is it best to use 800x600 as a guideline for all layouts? will that look best for all different resolutions?

you should use roughly 750x480. you have to take into account the scrollbars, menu, toolbar, status and url bars. it's different for netscape, ie, netscape (on apple) and ie (on apple) but roughly 750x480 should be ok.

the scrolling up/down is ok but not left/right (that's funky.) just try it out and see which looks good to you. definetely not 800x600 'cos that'll scroll left/right.

Umm .. there was a poll a few days ago, .. right here .,. >> http://www.lissaexplains.com/forum/showthread.php?s=&threadid=33579

about 50 percent use 1024 by 768. most people with some of the newer-ish(about less then 3-4 years old) tend to use 1024, because it's often the default.

Ouwldnt making it around 750x480-ish look really wierd in 600x800 and 1024x768? I dont think you want a page with no specific resolution thing. You'll have trouble making it look right in both, unless yopur doing a very simple tables/divs layout with the width in percents in all cells

you can't make your layout exactly 800x600 or 1024x768 'cos of the scrollbar on the right side. the scrollbar on the right uses up the available pixels. you have to make it slightly smaller. otherwise you're page will scroll left/right with a user that has 800x600 screen resolution (same thing with 1024x768.)

if you're making 800x600 it'll be ok for the 1024x768 user but not the 800x600 resolution.

From what I can gather, if you make a layout on a 800 x 600 screen, then the 1024 x 768 screen's will be able to see it. But the other way round will not work.
So make it using 800 x 600, and then most screen resolutions will be covered.

yes, jonathon put it so much simpler then i did :).

i usually build my pages for 800x600 so my layout width is 725-750 pixels. the right scrollbars and side borders take up about 25-50 pixels, i don't remember off the top of my head.

keep in mind that a user can customize the width of the scrollbar on their computer- so don't cut it too close by measuring your own and making the page the exact width because it just barely won't fit and you'd get an annoying horizontal scrollbar if the scrollbars are just a little bit wider. also, different browsers have different amounts of space available- for example, Netscape has the side toolbar on the left that takes up some, although very little space.