Reading Usable Help
@UsableHelp on Twitter
Gordon R. Meyer
Peter Merholz excavates a copy of the original Macintosh user's manual and finds it is an intriguing read, remarkably handsome, and filled with interesting explanations of now-common computer concepts. For example, the writers had to introduce users to such heretofore unknown affordances such as scroll bars and dragging. Merholz's write-up features large scans of the full-color photographs and other interesting commentary.
See also: Listen To How Far We've Come, for the audio instructions mentioned in the comments at the site.
Thanks to Daring Fireball for the link.