A variation on the "comments" idea is to use Data | Validation. With
this you can specify an input message, such that when the cursor is put
on that cell the message pops up. Although tied to a particular cell,
you could arrange for these messages to be in column A, for example,
which could be locked in place using Window | Freeze Panes, so that if
your co-workers have difficulty on row 9, they can just click on A9 to
get some context-sensitive help. These messages will not print out, and
you can define your print range to exclude column A.

Hope this helps.

Pete