I used to sell antennas years ago, and have installed my share. It all depends on where you are, transmitter locations, distance from you, and what channels you want to watch. You need to use the two links theoldwizard just gave you, and then determine the answer to the questions:
1. What channels do I want to watch
2. How far away are those transmitters
3. What locations are they at. Are they all on the same mountain top or building 20 miles away, or are they in 5 or 6 locations 100 miles away.
4. How much are you willing to spend.
In our case we decided on local stations within 40 miles, all in the same general location as to the compass, and whatever was best to do that. We went with a Channel Master antenna bought right from Channel Master, one of their preamps, a chimney mount, and the antenna pointed stationary at the compass point where most of our local stations are at. The reception is outstanding, we have other things we stream via the Internet, and the things we cannot get there we get off air. The antenna is light so an 8' pole on the mount was adequate. My neighbor has a two story, and he is using a facia mount with an even smaller antenna. We chose larger because we have to see thru/around some trees and two stories like his. I did not want a 30' mast on the roof and rotator like we used to do in the 1960's and 1970's. Be sure to adequately ground the mast and install proper lightning protection. Your system can get damaged from nearby strikes or even a charged cloud passing over you if you do not. I ran 6 ga wire as a ground into a grounding rod on the side of the house, and had my electrician tie that ground into the house ground just before the panel per codes. We also have an FM antenna that is omni-directional. It has its own ground and pre-amp. The whole system uses RG6 cable of a high quality. You will need special crimping tools to put ends on the RG6. The RG6 coax will reduce the multipath.
Or if the stations are closer, just use rabbit ears.
