Blend Modes
https://helpx.adobe.com/photoshop/using/blending-modes.html
Composite Examples: a round up
http://www.flickr.com/groups/photocomposites/
Joel Grimes: http://youtu.be/1c0_pLKtG5Y
http://thephotobrigade.com/2013/02/composite-photography-by-tom-di-maggio/
http://digital-photography-school.com/a-guide-to-create-eye-catching-composite-images
http://www.mediabistro.com/10000words/composite-photography-picture-is-worth_b322
Books to explore:
Photoshop Compositing Secrets: Unlocking the Key to Perfect Selections and Amazing Photoshop Effects for Totally Realistic Composites [Paperback] Matt Kloskowski (Author)
http://www.amazon.com/Photoshop-Compositing-Secrets-Selections-Composites/dp/0321808231
Layers: The Complete Guide to Photoshop’s Most Powerful Feature (2nd Edition) [Paperback] Matt Kloskowski (Author)
Adobe Master Class: Photoshop Compositing with John Lund Paperback, by John Lund
The Hidden Power of Blend Modes in Adobe Photoshop by Scott Valentine
http://www.amazon.com/Hidden-Power-Blend-Modes-Photoshop/dp/0321823761/ref=sr_1_6?s=books&ie=UTF8&qid=1378229846&sr=1-6&keywords=photoshop+compositing
Free Textures Here, Google free textures and see what you can find or snap your own.
https://www.brusheezy.com/textures
how to:
http://www.photoshopessentials.com/photo-effects/blend-textures-with-photos/
ARTISTS
Brooke Shaden
http://brookeshaden.com/gallery/
http://www.promotingpassion.com/
Rosie Hardy
http://www.rosiehardy.com/