There are probably many sites you find interesting. By subscribing to their feeds you don't have to revisit them again and again, just to see if there's something new.
On many websites you can see little orange images saying XML or RSS. If you copy the related URL and paste it into the proper place in your reader software, you will automatically receive all the updates.
(Another advantage is that you don't have to give any data, not even your name and email address.)
A nice software like that is Feedreader, but there are many other good ones.
On the right side, you can find a link to the feed belonging to this site. Don't forget to subscribe. :)