This article from Salon in May 1999 has a great summary of what blogging is:
“Weblogs, typically, are personal Web sites operated by individuals who compile chronological lists of links to stuff that interests them, interspersed with information, editorializing and personal asides. A good weblog is updated often, in a kind of real-time improvisation, with pointers to interesting events, pages, stories and happenings elsewhere on the Web. New stuff piles on top of the page; older stuff sinks to the bottom.”
Here are links to a handful of other articles about the history of blogging.
The Web the Way it Was (Wired | February 23, 2000)
Online Digests Help Readers Cope With Information Avalanche (New York Times | August 2, 1999)
Fear of Links (Salon | May 29, 1999)