Amazon didn't really let people know how to add feeds to their newsreader so I whipped up a page that can get you started:
Amazon RSS Feed Builder. You can build Book, DVD, or CD feeds with this little tool. Just choose a category or enter a keyword and you'll get the URL for the feed. Then you can copy the feed URL and paste it into your newsreader. If the RSS looks good (ie. has items), you should also get a preview of the feed so you can see what's in it. The feed builder hasn't been tested too much so let me know if you run into problems.
Here are some RSS feed URLs I built with this tool (that I'll be monitoring):
Try it out:
Amazon RSS Feed Builder.
Update: The feed preview is a bit sketchyso even if it says there aren't any items, check the feed manually to see if that's true.