Don't know about anyone else for certain, but I don't go out to a board and start looking things up unless I'm looking for an answer. A friend of mine who used to sysop some game areas online back when there wasn't a web used to always like to give cryptic hints rather than answers which used to drive me nutso.
I know when I go to a board that it is possible that I might learn more than I anticipated but have rarely found that such knowledge "spoiled" playing that particular area/puzzle myself. But I know that before I go reading the boards and feel it is my responsibility rather than those who have been posting help for others.
Frankly, I think players like "spoilers" or why would strategy guides have become the norm and why would there be so many help/spoiler boards and walkthrus about the web - people like to be able to look up the answers when they get stuck rather than spend hours fussing around trying to find some solution. The players who like solving it all on their own are going to do just that and not be visiting this or other boards for a "hint".
So my vote is just say what you have to say and readers accept the responsibility that they might get "spoiled".
Wyv