I would like to develop a site using jQuery that will work with all major browsers. I thought to start with a basic layout (a header, a couple of tabs with content, and footer).
Based on your described needs, I would highly recommend checking out the "Grids" css file from the Yahoo User Interface (YUI) library, you can find the file plus documentation here: http://developer.yahoo.com/yui/grids/.
The grids package's basic setup includes a header, body, and footer. You can remove the header and/or footer if desired. The body can be divided up using a nested grid model and a variety of templates are included.
Personally, I start off all HTML/CSS pages I make with the combined "reset-fonts-grids" file from YUI. It provides you with a cross-browser css reset file, the grids file, and some standardized classes for fonts.