CSS Positioning

Pixel
http://en.wikipedia.org/wiki/Pixel
Click this link for Wikipedia's encyclopedic description of pixels.

Mountaintop Corners
http://www.alistapart.com/articles/mountaintop/
This page describes a simple method of rounding the corners of graphic images by coloring a few pixels at the corners.

Visual Formatting Model
http://www.w3.org/TR/CSS21/visuren.html
Here's the full scoop on CSS positioning and floats as defined in the official (and woefully technical) W3C specifications.

CSS Positioning: Static, Relative, Absolute, and Float
http://www.christian-web-masters.com/articles/web_CSS-positioning-tutorial__page_1.html
This page offers a quick tutorial on CSS positioning and floats.

Relatively Absolute
http://www.autisticcuckoo.net/archive.php?id=2004/12/07/relatively-absolute
This site has a brief but useful description of CSS positioning.

Learn CSS Positioning in Ten Steps
http://www.barelyfitz.com/screencast/html-training/css/positioning/
Here you'll find a quick tutorial on CSS positioning.

CSS Positioning
http://www.w3schools.com/css/css_positioning.asp
Try this site for more useful information on CSS positioning, including techniques for handling overflow content.