Edit: 3/4/12 Kittysaysmeow-WQ had a slight problem using the render/light effects on Photoshop Cs5,using a Mac Os. To fix this problem you have to run Cs5 in 32 bit mode,kinda funny because I don't have this problem on a PC,but here are the steps
Step 1. Go to your finder menu and click on go.
Step 2. Click on Applications.
Step 3. Click on PhotoshopCs5 folder,then right click on adobephotoshopcs5.app then select get info.
Step 4. After the get info menu box opens select the general tab to expand it and you should see a box that says Open in 32 bit mode.Check it and this should fix your problem. Uncheck it to go back to 64 bit mode.
Or you can follow this link for another method,but I was told the above steps are more common.[link]
other features that don't run in 64 bit mode on Mac are....
Extract (Use Refine Mask under the Selection menu)
TWAIN (support works on some scanners)
Video Frames to Layers
Send Video Preview to Device
Edit: Phattyartist picked up on something I failed to mention.For those of you who are having trouble with the lighting effects render.(You Have To Be In RGB Mode, 8 Bits Per Channel,Sorry For Any Inconvenience This May Have Caused.)
Learn how to create your own dynamic rock textures in photoshop with this widely used technic. If you like this tutorial please check out my other tutorial on channels and color modes
If you have any questions let me know and I will try to answer them the best I can.