What is a blog?
"At their core, weblogs ("blogs" for short) are pages consisting of several posts or distinct chunks of information per page, usually arranged in reverse chronology from the most recent post at the top of the page to the oldest post at the bottom."

From:
Bausch, Haughey, Hourihan. We Blog: Publishing Online with Weblogs. Indianapolis, IN: Wiley Publishing, Inc. (2002): 7.

 

Examples of blogs...

BiblioBlog
Blah3.com Free Speech for the New Century
blogs.msdn.com
CNET News.com -- Technology news and business reports
The Daily Dish
David Davies' Weblog
Google Blog
Information Literacy Weblog
j's scratchpad
librarian.net
little red cookbook t h o u g h t i s f r e e
Newsblog
RealClearPolitics
The Shifted Librarian
Sketch Blog of the Day
T A B L O I D - N E T
Talking Points Memo by Joshua Micah Marshall
This Modern World
Turning the Tide
washingtonpost.com – White House Briefing