You are not supposed to put chicks on bedding it can pierce their skin and kill them. Also a heat lamp in all will cost about $10 if you get a regular sized one. Reptile heat rocks don't work well with chicks and are WAY more exspensive.
Keep them in a box with a heat source. If you are hatching them in an incubator keep them in the incubator for 48 hours they have enough nourishment in there system. If the mother hatched them keep them with her unless it is cold out she should take care of them if she is still broody. Keep food...