OK, this is how it works:
If you go to a USER's post and you think it is a good post (good info, user went above and beyond, etc.) then you can click the Scales
in the top right hand corner of THEIR post. A window will come up and allow you to click APPROVE or DISAPPROVE of their post and make a comment.
Always make a comment (gives the user more points) and click approve. You should not click DISAPPROVE (give negative points) in my opinion just because it could come back to haunt you (user will always be watching for you).
You can view the comments that user's gave you by clicking USER CP in the top left hand corner of the screen. When the new page comes up go to the bottom right and it should have Latest Reputation Received. You will have up to 15 comments from users (it used to only show 5). If you can't see any comments you either don't have any or you need to click the double DOWN ARROWS beside the points total. It will also show you for what thread as well. Click the thread title and you will see the post you received them on.
Once you get 100+ points then you will get 2 green squares beside your name. And so on for every 100 points. You will get points based on a users reputation. So for example, you will get little points from a new user but you will get more points from someone who has been here for a while that has a good reputation.
You do not get ANYTHING for the points you receive. It is basically just a pat on the back to make you feel good.
Try not to abuse the point system and just give out points for fun or just because. Do it because you really feel as though a user went out of their way or deserve the points. You don't necessarily need to give a user points BACK just because they gave you some.
And the green squares are only for reputation, nothing else.
Hope this helps.
-Matt