Editing CSS ends up being a lot of trial and error as well as time consuming. Being able to make changes on the fly, or even just seeing what the changes do, is really handy. If you use Firefox with the Web Developer add-on, you’ll be all set.

PICTURED ABOVE: the style for the header background is changed to red, on the fly.

Once Web Developer is installed, you can activate it’s toolbar from the Firefox menu: View/Toolbars. Then from its toolbar you can select CSS/Edit CSS and you will get a frame with the CSS file referenced from the page you are on. After changes you will need to save it to your hard disk and then upload it to your site. There are a number of other tools in the Web Developer toolbar too for testing and getting info on web pages.