RSS Feeds
If you see this icon 
on a page you can subscribe to the feed (It's FREE)
With RSS you can subscribe to a channel and when the content of the feed is changed you will be informed without having to keep returning to the site.
Although internet explorer now has a RSS reader built in you will get better results by installing an Aggregator (software that monitors and diplays RSS feeds)
One of my favourites are "Construtive IT Advice's RSS Aggregator"
Installers are downloadable here
or here
Another good Aggregator is " Sharp Reader"
