i used pellet things that were made, i believe, of pine.  for the first couple days i put those down with paper towels on top so that they would learn where real food and water was.  
the pellets were great because when they got wet they broke down into sawdust which sifted down to the bottom of the brooder floor.  no dust. no mold.  no wet.  once a day i would take a little hand cultivator and rake through the bedding  which would move the fresh stuff to the top and then i'd throw a scoop or two of fresh stuff in on that.  nice and clean.  once a week or so, i changed everything out.  one bag lasted me the 3.5 weeks that they spent in the brooder.