RSS stands for "Really Simple Syndication". If you have a web browser that supports RSS, you can look for the RSS icon (usually located in the address bar) when navigating through the categories of this site.
By clicking this icon, you can see a list of the most recent items in the category you are currently looking at. By bookmarking the RSS 'Feed' you can easily see when new items are added to that category (usually the number of new items will show up next to the bookmark). By clicking the bookmark you will see the items in a simple textual view, with links to the full graphical pages on the site.