Crumble up a cracker or feed em flakes. Treat them as if they were guppies. Keep the water above 75 and watch them grow. You may wanna get a couple of tanks. Id go nuts if my minnows lasted more than a week. I go through over 400 a weekend from spring till fall. If your wanting to raise them then just google it. Theres tons of sites out there that will give you a full list of supplies and detialed instructions. I wish I had the time to set up a fat head pool but I cant seem to stay outta my boat long enough.
Simple, just get a tank, aerator, distilled water from a grocery store since your water from the sink will usually kill them, and keep them COLD.If its winter if you can put them in your garage without them freezing then that would be the best. Other wise the basement would be good to.
I never feed mine and they live plenty long, I have had barely any die on me.
I keep a 10 gal aquarium in my garage with a filter and airator hooked up. I treat the water with BETTER-BAIT from BPS that makes the water blue and takes care of the chlorine and amonia. I may keep as many as 100 minnows at a time in the tank so when I'm ready to fish, I don't have to worry about stopping for bait. I feed them Tetramin fish food. They need a lot of air with that many minnows in the tank. My airator is the 110V frabil pump. So far this combination has worked just fine.
Try feeding them Cheerios or some other oat based cereal. this works great in minnow traps also! I have found that if you keep minnows in a small tank and feed them you will have to change the water often because it will sour.