While the Codex is being repaired after some malicious activity (a public display of the hanging will commence upon interception of all evil parties involved :-| ), you can still find a wealth of information from the Codex by using Google's search features and clicking on View Cached Page.
And don't forget that a lot of people have valuable information on their websites and blogs. Here are some specific resources but you can find more by just including "WordPress" in your searches:
Weblog Tools Collection
More WordPress Resources
WordPress Theme Viewer
Blogging Pro WordPress Theme Category
WordPress Design Sandbox Article
Working On CSS and the WordPress Theme (using a sandbox)
Template Tag Layout in simple to read form
The Loop in Action
Anatomy of a WordPress Theme
Secrets of WordPress Themeing
Secrets of WordPress Themeing Part 2
Templates and the is functions
And this is just the start of it. There are a ton of other resources available.