This is our first time with chicks. We have 8 - 2 Light Brahma, 2 golden laced Wyandotte, 2 Dominique and 2 buff orpington. My husband is a contractor and has an awesome "right hand man" who built us our brooder which is located in our garage. It's divided in half with a piece of plywood that fits into a small track so we can pull it out when they get bigger and also use it when we clean it - putting the chicks on the other side. My husband laid some cheap linoleum on the base for easy cleaning. We put a 12 inch corregated cardboard "wall" around the base to prevent drafts when they are really little.
We have two doors that open in the back so you can access either side or just open both to access it as a whole.
This makes for really easy cleaning. I have two waterers, one feeder, and a little sandbox (they just love).