From back cover:
In Gamemastering Secrets, Aaron Rosenberg and guest contributors cover everything about running a roleplaying game, from choosing a game system to closing out a long-running campaign. They give tips on how to handle various situations, pointers on potential dangers and how to avoid them, and advice on how to get the best gaming experience for everyone involved.
If you've never GM'd before, they teach you how to go about it, where to start and how to proceed, and enough tricks to convince anyone that you're a veteran.
If you are an experienced gamemaster, they give you new tricks, ways to keep your players on their toes, and ways to spice up your games.
For use with any roleplaying game (examples are drawn from the d20 and Fudge systems).