There is nothing different about caring for these babies than caring for the ones you hatched yourself. They need a place to be, bedding that is safe (paper towels the first few days and something like pine shavings NOT cedar ever after. They need to be warm -- a red light is preferred over a white light. At the beginning they should have warmth of up to 100* with areas away from the heat in case they get too hot, so you'll need a thermometer. They need food and water. Many people here suggest putting marbles in their water to keep the level shallow so's the poor things don't drown. As for food there is some debate between medicated and non-medicated chick starter. Seems to me a personal choice.
If there are problems -- lethargy, aggressiveness, spraddle-leg (sp.?) there are lots of answers here.
I put together a chick emergency kit that includes children's polyvisol vitamins, apple cidar vinegar, bandaids and a few other things.
By the time they are 6 to 8 weeks old they'll need a protective coop -- if you've raised chicks previously then you might already have a place, but it is suggested that an old hen house be thoroughly cleaned. All of this is a start.
Are your birds for meat, for egg-layer, 4-H projects? And again, Welcome.