A "blog" is a "web log", a website where someone writes articles, usually with newer articles appearing at the top of the page.
The cool thing about blogs is they are setup to easily be read by other applications, allowing you to see new entries from your favorite blogs without having to go to each blog to see if there is something new.
For example, click the "Add Content" link at the top left of Google's Personalized Home Page and enter "gethuman.com". Then each time you visit Google's personalized page, you will see the list of the newest articles from gethuman.com. When there is one that interests you, you simply click on the article name which will link you back to the gethuman.com website so you can read the article.
There are now blogs about any topic you can imagine. Poke around the Google's Personalized Home Page or My Yahoo! to learn more.
The word "blog" is going mainstream. Even "the new" AT&T now has billboard advertisements about blogs!
Use blog software such as Blogger (now owned by Google) or Typepad. The gethuman blog is authored in Blogger.
Many websites display an icon like this
to indicate that that website contains a blog feed.
A "feed" is a separate file automatically created
by the blog software which specifies the list of
articles on that blog. The feed is typically an "rss"
(Really Simple Syndication) file which is a very
specific example of an "XML" (eXtensible Markup
Language) file. Phew, aren't you glad you asked?
When you use
Firefox
(which I highly recommend) or Microsoft's Internet Explorer,
you should see the blog icon
on the bottom of the browser window
when the browser has detected the presence of a blog on the current page.
Click on that icon (usually on bottom right corner of your browser)
to add that blog feed.
(If you want to figure out how to get your blog "recognized", see the "rss feed" meta-tag on gethuman.com/index.html.)