To use Rss feeds you will first of all need to set up your catagories and feeds
Log onto the administration area
Select Catagories & Feeds
From here you can see the catagories and feeds already in place. You can see (Line 3 in here) you can add a new catagory.
Click Edit Rss Feeds
You will obviously need a feed source. Remember only to use feeds from sites that allow commercial use. The best way to transfer these feeds into the URL box is to cut and paste them from the source.