Oh hey, a reading list! Thanks!
This can't qualify as an ebook prize suggestion because it's well over $10, but anyone interested in the history of text adventures should check out 50 Years of Text Games by Aaron A. Reed. Absolutely fascinating.
I'm not entering the jam this year because I don't have quite enough experience, but I'll definitely be playing other people's entries, and this jam is absolutely going on my calendar for next year! Keep up the good work, guys!