Just about everyone online these days has an RSS (Really Simple Syndication) feed.  Essentially this is an easy way to get content from all of those blogs, wikis, news sites, social bookmarking sites, and a whole lot more.  Instead of you going to the web sites of each individual web site, you use a reader application to track the feeds you want to follow.  When you check your reader it will indicate which sites have new content.  You can then either read the content right there in your reader OR go and visit the site.

In today's world of a web that is constantly being updated, this is really the only way to stay on top of things.