Yah, I get it. You've answered the same elementary bleepin' question a zillion times and you're tired of hearing it. I understand the temptation to just tell the questioner to buzz off. But if you do, you've just created an enemy. Never a good idea.
There's always the temptation to just tell somebody to "do a Google search". Don't. Give it a try (turn Safe Search off; you may get a surprise!); you'll find that it invariably brings up all kinds of garbage along with the good stuff. The reason people need answers in the first place is that they can't necessarily tell the good from the bad.
The answer, developed early in the history of the Internet (long before the Web!), is the list of frequently asked questions, or FAQ. You simply take all those questions that you're tired of hearing and put them into a list, along with answers. Then, when some clueless newbie asks an elementary question, just send him a pointer to the FAQ, perhaps with a note "see number 12"
- The tone must be as neutral as possible. Anything starts out with some variation of "you jerk!!" isn't going to do any good at all. Beware of adjectives.
- Avoid loaded words. "Rape", "murder", "genocide", "terrorism", and "treason" are the ones that I've seen misused the most. Most dangerous of all is attempting to redefine loaded words -- if you refer to someone as a Nazi, be sure that they really were a member of the Nationalsozialistische Deutsche Arbeiterpartei.
- Learn what Marxist dialectic looks like. Avoid it like the plague. Older people (like me, for example) have a nasty trigger response to it.
- Use real questions. I've seen too many "FAQs" answering questions that I can't imagine anybody actually asking. Some is axe-grinding, some is market-speak, some is just plain cluelessness.
- One of the most useful things you can put into a FAQ is a list of "magic words". To someone not familiar with a field, it's often not obvious what search terms to use. Use the wrong terms and you'll get buried in drivel. For example, if you're looking for instructions on how to do something in Linux, the Magic Word is HOWTO.
- Avoid the "all X are Y" fallacy. It's ether false, a tautology, or a definition.
- Be careful of "if X then Y" constructions. People tend to ignore the "X" and argue with the "Y".
- When possible, frame things positively. People often don't hear the "not" in a statement and will think you said the opposite.
- Be very careful with terminology. Words mean different things in different contexts. For example, "freedom of speech", "treason", and "fair use" have specific legal meanings. Make clear when you're using the technical instead of the popular term.
- Know the difference between an elementary question and a stupid question. Answer elementary questions; ignore stupid questions. The main "stupid questions" I deal with are the ones that have already been answered, the ones that are wildly off-topic, and the ones that are out-and-out loaded. That said, you don't need to write a textbook if your subject depends on an understanding of, say, calculus. Point them to a real textbook.
- Learn about primary and secondary sources. This is Research 101, but it's amazing how many people don't know the difference. Reports of scientific research in the popular press are infamous for getting things backwards.
- References to respected authority are always good. After all, one of the reasons you're writing your FAQ is that you know enough about your subject to know who the "respected experts" are. For this FAQ HOWTO, see "Language in Thought and Action" by S. I. Hayakawa.
- Beware of wikis. It's too easy for axe-grinders to get in and mess things up. The Wikipedia article about a friend of mine is wildly inaccurate and borderline libelous, for example. (Wikipedia's "edit wars" are infamous.)
- And speaking of Wikipedia, remember that it's the first source for everything and the final authority on nothing.