I feed chick crumbs for about 7 weeks then move them on to grower / finisher pellets and mixed corn. They will need to be kept under a heat lamp - red bulb is best - for about 4 weeks, depending on teh weather and how quickly they feather up.
Remember day old chicks are very small and pretty dim - they can get through very small gaps and wander away from the light and die very quickly, so mke sure whatever you are keeping them in is secure