2D - How do you set the order in which game objects appear on screen?

Hey, I'm VERY new to unity - and development in general - and I have a quick and simple question. I've got two objects - a player (generic human sprite) and a cube (screenshot: http://puu.sh/d8GcN.png). Right now when the player walks into the cube he gets hidden by it (http://puu.sh/d8GdP.png), and I want him to appear above it. How can I do that?

Sorry for my total lack of experience. I'm working in 2D, using Unity 4.5. Thanks in advance!