In the early 1990's, there wasn't a book about the practice of unschooling. There was Teach Your Own by John Holt, but it said "you can do it," and didn't talk much about how, and John Holt wasn't doing it himelf when he wrote it. And he had died in 1985.
There were discussions on message boards at AOL, and once a week I ran a text chat for two hours. I saved and edited those, and people could download them as word files.
After a while, there came to be a set of e-mails that people could request. It was the closest to "a book," until The Unschooling Handbook was written, by Mary Griffith in 1998. Mary Griffith shies away from unschooling now, but some of the others who were involved in those early days kept with it solidly and are still writing and helping others.
But the barrage was a set of e-mails I used to mail out when someone requested it. After a while Monica Molinar, in Alaska, took over the mailings.
There were nine items for most of the time. I'll try to gather and link them, as I find and code them from Word to html.
Unschooling to Go
Genius Class to Go (2nd half of that page)
Unschooling Chat (Definitions, November 1995)
Unschooling Discussion from October, 1995
Gems from John Holt