WordPress Hacks

WordPress Hacks was launched nearly three years ago for reviewing WordPress themes, plugins, as well as providing tips and resources to the community.

It is one of the best places to start learning how to hack WordPress, I know first hand cause I visited it a lot when I started coding for WP.

BlogOhBlog

Great source of both free and commercial themes as well as WordPress tips and tricks.

WpRecipes.com

Serving up delicious WordPress recipes since 2008.

Weblog Tools Collection

One of the original and premier sites about WordPress.