Learning CSS Layout
Some Good Links to get your started
Css Basics.com - Very good site to start learning CSS from.
Developing with Web Standards - Overview of how HTML/Standards/CSS all fit together.
Float Tutorial Good introduction to the float property, which is the foundation of most layouts
Coloured Boxes Example technique for building site layouts.
Layout Gala a collection of 40 CSS layouts based on the same markup and ready for download!
glish.com CSS Layout techniques a good resource for learning some basic commonly-used layouts.