Pages tagged blending:

An Explanation of Photoshop Blend Modes
http://www.myinkblog.com/2009/07/14/an-explanation-of-photoshop-blend-modes/

great explanations plus photos to show you or download and "play along"
An Explanation of Photoshop Blend Modes
Adobe Photoshop Tutorials | High Dynamic Range | Adobe Camera Raw | Layers Magazine
http://www.layersmagazine.com/exposure-blending-in-photoshop.html
Exposure Blending in Photoshop