A hanging kit is included with most swings and should have the hardware and the chain needed to hang the swing. Some of the less expensive swings do not come with galvanized hardware or a galvanized chain, so they need to be replaced after about a year due to rust. If you do not replace a rusted chain, it will break. It might be better to just discard the hanging kit and purchase hanging materials that will last. Remember to measure the height of your porch to determine what length chain to buy.
Install the hooks on a solid overhead beam. It should have a clearance of at least 6 feet, 6 inches. Space two bolts or screw hooks in the beam the length of the swing. These will hold the chains. Drill some pilot holes to hold the screw hooks or bolts to avoid having the wood split when you screw the hooks in. Do not drill the holes too big or the hooks will come out when there is weight on the swing. Check that you have at least 2 ½ feet in front of and behind the swing for it to swing freely.
Use four chains, if possible, to hang the swing. Two chains will hook onto each bolt. One will go to the front of the swing and the other to the back. The standard height for a comfortable swing on an 8-foot porch can be found by using a 7-foot chain. This will keep the swing about 18 inches off the porch floor. Make sure all the hardware is properly installed before you hang the swing. You will need a few helpers. Get on a ladder and have your helpers lift up the swing and the chains to you. Hang the swing on the hooks, and adjust the chains so that they are even. If you want the swing to tilt backward a little, adjust the chains. Add some cushions to the seat to make it more comfortable.
To keep your swing looking like new, treat it once a year with a wood sealer and preservative. These can be sprayed or brushed on the wood. Check for loose boards, and tighten them when necessary.