Do we have to close our queries once resolved? If so, how can it be done?
Yes. When you get the answer that solves your problem, you accept the answer by putting a green check mark on the left side of the answer. You can only accept one answer as the correct one.
However, you and others can vote up (or vote down) the accepted and/or other answers.
The question is not closed and others can provide more answers even after you have accepted one as correct. There are some exceptions.
The question can be closed if it is determined to be a duplicate, off-topic, unclear what you are asking, too broad, or primarily opinion based. In these cases no answers can be added once a question is closed.
Hope this helps
What should I do when someone answers my question?
The first thing you should do when someone answers your question is vote on it, like any other user does. Vote up answers that are helpful and well-researched, and vote down answers that are not. Other users will also vote on answers to your question.
Going by the amount of questions that have been answered yet no accknowledgement from asker or anybody else has voted. Voting is not being used as effectively as it could and after being reminded of what is said in the link @Alaa gave actually proves there is need for discussion of this question being asked especially after considering the fact 133 metaanswers to one answer metaquestions have not been voted on or marked as accepted. Some even being accepted and yet not been voted on! One thing i get from rereading the mentioned link is do not hold back on down voting if you feel the answer is not worthy of an upvote and then comment. You could always upvote after any edits if you think it is worthy of such. People are just not voting one way or the other. Maybe it is sheep waiting for others to vote which is indicative of cliquish behaviour from many users and is taking away from the intentions of the voting system.
The point being what i think is; If you read a question and you think it is not worthy of an upvote then downvote it and comment why!
Go get voting.
How many first posts etc on main site are reviewed but have no votes?... The problem is not just with new users!