Brooder was oval (4'x2 1/2') shaped with no corners to possibly smother litter birds that are huddled together for any number of reasons. I set the brooder on 3/4 plywood to facilitate movement & lifted it up on to a small table to hold it high enough to work with the birds and to protect them. ON the plywood I placed cardboard; on the cardboard I placed paper (to collect and gather the bedding) then placed 1" of aspen bedding available at pet supply stores. Then covered the entire brooder with heavy cloth to help regulate the heat during first couple of weeks, leaving one side of the top open.. Replaced this cover with screen after second week.
I changed the bedding easily by lifting brooder wall and sliding paper out then sliding new paper in; put new bedding down on the new paper. Raise your food & water (from the base, not on top of the bedding) up to the height of chicks back using blocks of wood... adding wood blocks as they grow. This will keep the water cleaner, I used 1qt mason waterer and a 3-4 cup small chick feeder suspended the feeder from the copper pipe. These will not spill or leak and will keep food and water clean.
DOUBLE SECURE THE HEAT SOURCE BULB or whatever you are using for heat. This will save your birds... Have heard of many burned to death when light or heater fell into the brooder. I suspended my IR light from a solid copper pipe that ran end to end of the brooder where it was secured to the brooder sides and would not move. I secured heater's clamp with a small bungee strap to the copper pipe. Use red outdoor bulb if you don't have IR, they will be less inclined to peck at each other with the read light as a source of heat. Also you can leave it on 24x7 with no adverse effects.
Good luck --- Have fun!