The talented Jim Christensen gave an excellent presentation on compositing to an audience of nearly 40 attendees at the October 24 Technical Series meeting. Compositing is the art of combining elements from more than one image into a unified whole. Jim gave an introduction to the long history of compositing in photography, going back to the 1800's. He then showed a number of striking examples from his own body of work and then he demonstrated his process step by step for several images, using Photoshop tools to select, layer, mask and adjust the images to achieve the desired effect. The information on how to make these changes non-destructively could be applied even to single images, so it was valuable even if you don't plan to do compositing yourself.
Jim had a two-part course on how to use layers and how to fix common problems in Photoshop available for sale at the end of the presentation, and they proved to be quite popular.
You can download the pdf of Jim's meeting handout at this link.
To see Jim's work visit his web site.