There is a new e-book in town, this one covers RSS in depth from a publishers/marketeers point of view, and you can pick it up over at MarketingStudies.net right now.
The book, Unleash the power, covers all aspects of RSS, how to make your feed, RSS vs Mailinglists, how to promote it, how to use it. The author Rok Hrastnik has picked the brains of 30 odd people, marketers, publishers, RSS developers, consultants, yours truly included, so that you don't have to. We sent them honest answers to 30 questions on how to best use RSS and that's been worked into the ebook. If you need a primer, this'll be it.
* update, link removed as this is an ancient post.