An RSS feed allows you to keep up with the latest changes on your favorite websites without actually having to visit the website yourself. When something new appears on the website, a program called an "RSS Reader" will notify you that something's new and usually give you a summary of what changed.
If you don't have an RSS reader already, the first step is to get one. There's a massive list of RSS readers here. Sharp Reader on Windows and Straw on Linux are reasonable choices. Google Reader is another option, implemented completely within your web browser.
Thumbnails of each new photo sent to your reader:
New messages on our forums: