You are going to have a huge cat population in a year if you don't get them spayed and neutered when they are old enough.
You want to keep cats that are going to live outdoors like that cooped up inside some place like a barn for awhile, like a month. Bring them food (dry kibble is fine) and water of course but encourage them to hunt. After a month is up you can let them outside but keep putting the kibble out there. It keeps them coming home and helps steady their diet. Make sure they have places to escape to that are set up for them and too small for a predator to enter such as a cat door.
You will want to vaccinate them, treat them for worms and put flea prevention on them as well, so you have taken on a lot of pets. Try to find a low-cost spay-neuter clinic and you can get a lot of these services at a discount. Good luck! My cats are great mousers, they just can't get the big things like racoons, skunks, possums, etc.