Some of my favorite tutorials found on the web:

Photoshop CS3 Tutorial for Landscapes

Christy Schuler gives a WONDERFUL tutorial on how to clean up portraits

Tutorial on Merging HDR in Photoshop CS3-CS4

Stuck in Customs by Trey Ratcliff opened my eyes to HDR. My goal is to aspire to this greatness!

Photomatix Pro - This is what I used to get started with HDR (before I got Photoshop CS3)

Photoshop addons, filters and plugins.

virtualPhotographer is my favorite Photoshop plug-in filter. The possibilites are endless!