The first blog
It isn't clear who created the very first Web log, or blog, but it happened in 1997.
Winer claims that the first blogs were inspired by Scripting News, which Winer himself launched on on April 1, 1997. According to Winer, Scripting News is the "longest currently running Web log on the Internet."
Barger, on the other hand, invented the term "WebLog." In December 1997, he created RobotWisdom.com, a day-to-day log of his reading and intellectual pursuits, which he claims to be the first 100% Weblog. Winer site, by his strictest definition "wasn't quite a blog--he mixed up the reverse-chronological ordering too much."
Finally, "sometime in April or May of 1999" Peter Merholz abbreviated and de-capitalized "WebLog" introducing the term "blog" when he posted on the sidebar of Peterme.com the following:
"For What It's Worth
Peter Merholz recalls: "I didn't think much of it. I was just being silly, shifting the syllabic break one letter to the left. I started using the word in my posts, and some folks, when emailing me, would use it, too. I enjoyed it's crudeness, it's dissonance... As I wrote Keith Dawson after he added "blog" to Jargon Scout
I like that it's roughly onomatopoeic of vomiting. These sites (mine included!) tend to be a kind of information upchucking.
References and useful resources: