Audible.com - an great audio book/publication service that I have been using for about a year - has published a whole set of RSS feeds so you can subscribe to find out easily what new content is published, including both free and pay-for selections:

This Week's Best Sellers (Top 50)
 

This Week's New Audiobooks and Programs
 

New Free Audio Programs
 

Under $10 Audio Programs
 

New York Times Best Sellers
 

BusinessWeek Best Sellers
 

Publishers Weekly Best Sellers
 

Best Sellers in Arts & Entertainment
 

Best Sellers in AudibleOriginals
 

Best Sellers in Biographies and Memoirs
 

Best Sellers in Business
 

Best Sellers in Classics
 

Best Sellers in Comedy
 

Best Sellers in Drama and Poetry
 

Best Sellers in Fiction
 

Best Sellers in Foreign Language
 

Best Sellers in Great Talkers
 

Best Sellers in History
 

Best Sellers in Information Age
 

Best Sellers in Kids
 

Best Sellers in Mystery
 

Best Sellers in Non-fiction
 

Best Sellers in Science
 

Best Sellers in Science Fiction and Fantasy
 

Best Sellers in Self Development
 

Best Sellers in Speeches and Lectures
 

Best Sellers in Spirituality
 

Best Sellers in Sports
 

Best Sellers in Travel and Adventure
 

And perhaps the coolest thing on the page? I scrolled down and noticed the question "Where can I find more information about RSS?" and the first resource listed is the RSS Quickstart Guide from Lockergnome.com - nice.