There have been discussions of this before. I think the reason why we don't have anything like official guidelines is that most of what one can say about how to vote is either obvious or controversial.
Here are my own principles:
I think almost everyone would agree with the first principle. The second and third seem obviously debatable, and in particular I know that some people think one should never take earlier votes into account when deciding what to do with a post or comment. The fourth and fifth seem more often agreed with than disagreed with in public, but it seems clear that not everyone acts that way and politically charged topics seem to attract more opinion-based voting. Almost everyone agrees with the sixth. I'm not even sure whether I agree with the seventh.
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.