Building sites that work accross a wide range of screens/devices is referred to these days, as "responsive design" and the technique partly, relies on using @media queries. The stumbling block at the moment, is what to do about images. Making images responsive is not so straightforward. This will give you an idea: http://forums.adobe.com/message/4349178#4349178 but it is also a talking-point on the web so if you Google that, you will get plenty more!
Liquid layouts are also not the easiest things to implement. Nancy O has a template you could look at here: http://alt-web.com/TEMPLATES/3-col-liq-layout.shtml and if you Google it, you will find plenty of other resources.
I do think that your reliance on images and tables for structure and content is going to cause you some difficulty. These are not flexible design elements whereas, divs with percent or em base dimensions, where content determines the height of an element are.