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 Sites
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.