Introduction to Photoshop

In this walkthrough, I'll introduce new users to Photoshop to the following things:

Workspace
Toolbar
Selections
Layers
Text Tool
Color Picker
Saving for Web

And we'll use this file for all of it!

Extra help

I'd start with the Photoshop help pages at Adobe. They're quite good.

Then I'd go to Lynda.com and see which courses there appeal to you!