Cold Frame Using Old Window From Remodel

I have never built or used a cold frame before, being in zone 5a I think this is a wonderful idea for cold weather crops. This one I found on a post at http://www.theeasygarden.com/ and can see that I have most of the materials already to build one like this one.

Mine will be much larger and once I get a better understanding of how they work, I will be off to build my own. I already found a perfect location that gets sun through most of the day. 

Do you or have you ever used/built a cold frame?

I am interested in gathering more information that will assist me in build/using mine to live a more self sufficient life.