I dont know how to mark a best response.

That had me stumped too. When you go into discussions I've started you should see in blue lettering mark as best response over each person that replies to your post. Pick the one you like best but you can also rate each one as positive or negative. I understand those dont' change the amount of incentives awarded but the numbers on poster's stars. You'll get a star with a number in it when you reach a 100 too.

I've been wondering about this too. I've really wanted to know about the unresolved discussions. I don't think any of my discussions really have enough responses yet to mark a best response. Thanks for this post.=)

I know it is hard for me as well. What I do to figure out who I am going to rate my best response, is I look at what I was asking and see if someone answers all my questions and goes into somewhat of detail on it. I think it really is just your personal preference. Good luck and happy mylotting.