To start using RSS, you can use one of several custom web portals. Once you have set up your web portal, you simply subscribe to the RSS content feeds you want.
In addition, there are several desktop software readers that you download and install on your computer, many of which are free of charge.
List of news readers (Yahoo)
To sign up for RSS feeds using a desktop news reader, simply right-click on the orange RSS button, select "Copy Shortcut" or "Copy Link Location" and paste the address into your news reader.

For more information about RSS, visit Wikipedia.org.