QH has some good points. And yes they can be feast or famine. I did it for 9 years straight, releasing adult flight conditioned birds, educated by Spaniels.
The dogs harassing them made them jumpy at release time. I got it down pretty good. You want to get an incubator that does the turning on it's own so you don't have to go in all the time changing the atmosphere. I have a GQF Sportsman. It holds about 400 eggs. with 4 roosters and about 30 hens you can get about 1,000 chicks give or take a few. I have an average of %80 success rate, when things go good. An incubator with a humidistat would be the best. I plan on an add on for mine when I do it again. Good success is weighed heavy on the proper humidity and temp. once it is set it works great. Then keeping the chicks at 100 degrees is tricky. Thermostat controlled heat lamps would be the way to go. with one regular light that stays on all the time. If you want to profit from it you will need to do all these little steps to keep live rate high. And get food in bulk as said. You will have to sell birds at $6 or higher, and the longer you have them the more they cost. You will be better to give a fair attractive price right off and sell all right away as good strong fully feathered fliers. Say 14-16 weeks old. There is ways the big growers start them laying earlier on lights, this helps them get a jump and older birds sooner in the year. In order to make good you will have to have things go well and raise a few thousand birds. I have not went that big and just buy the feed at the elevator or fleet farm by the bag, that costs too much. You can use some grain screenings free from someone if you clean it up at an elevator, or cracked ground spillage in the roller mill. This can be fed to adults later and will save there. But chicks need good stuff. Cocksidosis can set in and wipe you out, so you want to know how to medicate for that if you see it start in on the flock. They are the dumbest creature on earth to raise, very good at killing themselves. After I tweak what I have doing what I said above I will do it again, but not until then. I have had up to 90% hatch just to have 250 die 4 days later because they get too hot while your at work. You need river rock in the water so they don't fall asleep and drown in it, and fresh greens and sod, along with several things to let them peck at, or they kill each other. When they first go out, you need to chase them in and out for awhile, and in at night so they don't pile and die. You need to mist them to generate oil. If a storm comes you want them back in. All until they have full plumage and have been wet a few times. At about 8 weeks they can be left alone with out side shelter. You want plenty of room and use blinders. The bigger the pen the better, or they will cannibalize. This is just a beginning.
But no matter what anyone says, a propper release program works very well. I can show you dozens of places that had nothing much, and after a few years there self sustained and flurishing, and lots of em. It flat out works. Good cover, a few to start with. A good # released after season closes, food for the winter and preditor control. Along with the land owner not letting people go murder the first couple years. Always have 1 strong area they like you never go. That, if they fly over there spot, its there safe spot.