How do I set up steam leaderboards?

Hello, I came across a problem which I find rather annoying. I can’t get steam leaderboards to work. What I want is a number in the bottom left corner of the screen with the best time for the current map but it seems like I can’t write to the steamworks leaderboards.

http://imgur.com/9fiXWnZ

http://imgur.com/REdHq9S

Could someone please help me?
PS: something went wrong with the pictures, you have to right click on them and open in new tab