If you aren’t shooting RAW files with your digital camera (as opposed to jpeg files), you should think about the advantages of shooting in RAW. Read the article RAW vs JPEG Camera Files at my photography web site.
A lot of the quality of your final image will be determined by what you do with your RAW files when you open them in Adobe Camera RAW (ACR).
When it comes to ACR, the name you need to know is Bruce Fraser. He was an internationally known Photoshop expert. Just buy Fraser’s Camera Raw book for your version of Photoshop. Recent versions have been updated by Jeff Schewe who is listed as the co-author.
Russell Preston Brown, Sr. Creative Director for Adobe Systems: “If you want to understand Camera Raw, then look no further than this book. Trust me on this one.”