I've got an HDTV, but don't know how to get HD Broadcasts.

If you have an HD Built in TV you need a High Def signal either from Cable, Satellite or Antenna. If you have cable, but don't have an HD Cable box you can contact your cable company and they will come out with a new box for you and your monthly fee will go up $10 or so. For Satellite you will need to upgrade your box to HD if it is not, and possibly your Satellite Dish (contact your provider). My personal favorite way of doing it is through an antenna. The reason for this is that depending on where you live you will be able to receive all the local broadcasts for free. Some of the cable companies offer local high definition channels, but not all of the channels are available through all providers, and with Satellite they haven't launched full coverage of local channels. If you live in/near a major city you can be guaranteed to have 5 - 15 HD channels available to you via an Antenna. To find out what's available go to http://www.antennaweb.org/ and follow the directions on finding the right antenna for you. This site will help you to find the right antenna for HD - its for outdoor or attic mounted antennas. If you don't want to mess with an outdoor or attic mounted antenna, take a look at the Terk TV5 amplified antenna, available at Best Buy and Circuit City for about $50. Its constantly rated as the number one antenna for HD use (non attic/roof mount). I hope this helped.