Choosing an antenna for your HDTV reception
There are two main types of antennas in use today: multi-directional anduni-directional. As the name implies, mult-directional antennas pick up signals from multiple directions
Reception - Omni-directional vs uni-directional
Strength per channel
It is important to know that a given antenna will not pick up all channels equally. If you were to plot the channels vs gain on a graph, the graph would generally look like an upside-down 'U' and there are usually a couple of dips along the way. This fact is what leads to the multitude of antenna designs out there for a given band. If it were not for this there would only be need for one type of UHF antenna, one type of VHF antenna, etc.
Once you are armed with this knowledge, how do you make use of it? Well, now it is time to head over to sites like AntennaWeb or TVFool. At these sites, you can enter your address and they will list out what channels are in your area, what direction they are in relation to the address that you give, what frequencies they occupy, and what type of antenna you need to pick them up. This should give you a pretty good idea of what you will be looking for when it's time to head out to the electronics store for that new antenna that you will be erecting in/on/behind your house.
At this point, I hope that you feel a little more knowledgable about antennas in general. If so, please feel free to drop a line in the forums. If not, please feel free to drop a line in the forums. I'll be happy to try to answer any questions that you may have. As always, we are here to serve the readers!