In general, the first thing you need is something called a news reader. There
are many different versions, some of which are accessed using a browser, and
some of which are downloadable applications. All allow you to display and
subscribe to the RSS feeds you want.
Once you have chosen a news reader, all you have to do is to decide what
content you want. For example, if you would like the latest DSM's Corporate
Press Releases you can subscribe to the feed in various ways, including by
dragging the URL of the RSS feed into your news reader or by cutting and
pasting the same URL into a new feed in your news reader.
Some browsers, including Firefox, Opera and Safari can automatically pick up
RSS feeds for you. For more details on these, please check their websites.