Sieben Design

Manual page for Migrations
Nothing beats reading up on the source documentation for a particular class. Migrations are one of those powerful and perhaps underutilized features of Rails. I like to keep this man page within reach.

Rounded Corners
This tutorial still makes use of images, but it seems well executed. Rounded corners can be a very stylish addition to most any CSS layout.

Dave Shuck's introduction to the DOM
This is a very accessable introduction to valid DOM coding with Javascript. It mentions the importance of valid (standards-based) code, and points out some potential flaws in div-swapping.