Here's a post where I built mine almost two years ago. I've tweaked and changed a few things since, but overall they have worked very well for me. The best part of the whole gig is the septic system I installed. Having dogs on concrete requires an (almost) daily washing, but it's much cleaner and no odor.
I recently built a real nice puppy pen, and will have to post a few pics of that and some pics of my newest yellow pups later.
http://www.easttexashogdoggers.com/forum/index.php?topic=7028.0