Original Macintosh User Manual (everything needed an explanation)
peterme.com
peterme.com
Another interesting issue around help -- people often think that if something is really well designed, users won't ever need to get help. That's true for the most part, however there are important exceptions. When your product enables users to do something which they've never been able to do before, you can't expect that they won't need some help understanding what it is. Groundbreaking stuff will probably require some explanation. The original mac is a good example.