There is what sounds like an interesting and well-researched book coming soon called "Shareware Heroes". Authored by Richard Moss, a long-time video games journalist, it chronicles the indie shareware scene of the 80's and 90's, including inside interviews with some of the important figures.
Moss describes the book as follows:
Shareware Heroes: Independent Games at the Dawn of the Internet takes readers on a journey, from the beginnings of the shareware model in the early 1980s, the origins of the concept, even the name itself, and the rise of shareware's major players – the likes of id Software, Apogee, and Epic MegaGames – through to the significance of shareware for the ‘forgotten’ systems – the Mac, Atari ST, Amiga – when commercial game publishers turned away from them.
This book also charts the emergence of commercial shareware distributors like Educorp and the BBS/newsgroup sharing culture. And it explores how shareware developers plugged gaps in the video gaming market by creating games in niche and neglected genres like vertically-scrolling shoot-'em-ups (e.g. Raptor and Tyrian) or racing games (e.g. Wacky Wheels and Skunny Kart) or RPGs (God of Thunder and Realmz), until finally, as the video game market again grew and shifted, and major publishers took control, how the shareware system faded into the background and fell from memory.
Currently the book is raising funds on Unbound, click here to preorder Shareware Heroes (digital or print) and help get it published!