How many channels does it get you? This will vary based on location, but for $32 seems like a good investment.
That will tell you if a set top antenna is good enough or if you need an attic or exterior antenna.
Will let you know off all channels available in your area and which direction they come from as well as which height the antenna needs to be for them.
Typically you can use a simple unpowered unit and pick up everything if you're in a good location. A $10 wal-mart set of rabbit ears will work.
You can also use audio wire around a high window cill an connect it to the unit if you have signals on seperate sides of the house. Cheap pick up for a spool at radioshack.