how do you vote on a best answer? Is that when it's someone else's question?

Answer 1

well, actually, you can vote on best answers on your own questions.

see, the question only originally has like 3 days or something. but for the most part, after a day, or even less time, there will be no more answers, generally.

after the question has ...expired... which happens after three days (unless you extend it), if the asker doesn't select a 'best answer' it will automatically go into voting, which lasts for 2 days, but will go longer if there is a tie, or no votes.

[note: the asker must select a best answer within the LIFE of the question, not after the three/seven days answering period]

at this point, the answerers, the asker, and anyone else that wants to may vote on a winner.

there are a lot of questions still in vote, which is a shame, because that's a LOT of orphaned questions, but not many people vote.

Answer 2

Look above and see: there's 3 categories: Answer (open questions), Discover (resolved questions) and Vote (undecided questions). Choose Vote and look at questions there. They're questions asked by people other than you and are not decided yet. You choose the one you think is the best answer and get 1 point.
Hop that helps

Answer 3

yes...