Or perhaps the proper term is "second-degree plugging". I just wanted to point folks to the GM's Field Guide To Players. It's a sourcebook on how to know and handle your players as a GM with cover art by my lovely wife, NJ Huff.
This is especially good news since NJ is still recovering from a significant injury which has prevented her from working on her art for about a year. So completing this piece of art was a big deal for her (and getting paid for it didn't hurt). Since you probably can't see much of the cover above, here's a larger version (click for full-size).
NJ will also be working on a new cover for Jade Arbuckle's other book, so I'll make sure to include that in the future. So, check the book out and any RPG authors out there should certainly keep NJ in mind for their own projects.