Every visitor has a screen that they will view your web site on. Laptops have LCD screens, desktops have CRTs and LCDs of varying sizes. Your first step in designing the site is to research the most common screen size of the day. Then your design should fit nicely in that space.
My recommendation is that you design the site, if at all possible, to stretch. This way if the most common size is 1024 x 768, but someone comes along with a screen of 1920 x 1200, your site will stretch to fit the space. This method means your design will fit nicely in any space your visitor has.
The alternate form of design is to design for a particular size (say 800 x 600) and put a color background on the page, and either center or left justify the design. This is fine as long as the visitors come with a fairly close screen size. But when that visitor comes along with a huge screen, and your tiny design is in the middle of their screen, it looks a bit out of place.
Oh, and don’t forget about shrinkage. Yeah, a log of folks surf the web these days on their BlackBerrys, iPhones, or other smart phones. If your design does not shrink, they will have difficulty seeing what is on the site and finding what they came looking for.
Test your site design before you build too many pages with multiple browsers, multiple screen resolutions, and multiple devices. Check it out on your smart phone (or have a friend do it). It will be worth your time doing so.
