LiveDocs to the Rescue!
Sometimes you will find that the Help feature may not offer complete assistance on a specific topic. Documentation for software often changes and expands, and LiveDocs is Adobe's answer to this problem. If you go to www.adobe.com/support/documentation, you can access online documentation on all of your Photoshop topics. The good part about this documentation is that it is developed on a collaborative level, allowing the community to chime in on questions and answers to the topics at hand.