Alex King's theme browser does not come close to covering all 400+ theme that are available to WordPress users, and most of the themes listed on it are out-of-date. I recommend that you replace that listing the the WordPress Theme Viewer: http://themes.wordpress.net/
You should also consider adding a listing for the Codex: http://codex.wordpress.org/
And, you should consider adding a listing for some of the high-quality articles in the Codex, like those listed under the "WordPress Lessons": http://codex.wordpress.org/WordPress_Lessons
And, a few more suggestions:
The FAQ: http://codex.wordpress.org/FAQ
"Combating Comment Spam": http://codex.wordpress.org/Combating_Comment_Spam
The plugins listing: http://codex.wordpress.org/Plugins
Other than that, it seems to be a good collection of resources.