I need to find a list of people with contact information (emails or
mailing addresses) who want to purchase land for commercial use (like
a franchise).  My father has a piece of property located on a busy
road that is rapidly being developed in Manalapan, NJ (07726 is the
zip).  It's highway frontage, zoned commercial and approx 5-6 acres. 
My father would like to bypass a realtor and contact interested people
directly to see if they want to buy his piece of property.  Websites
where we can post the land info and sell directly to an interested
buyer would also be much appreciated.

Personally I would employ a sign writer.

Stick up a board saying 'For Sale'

Anyone who is interested property in that area will eyeball what is available.

Because brokers bring the best sites to users (Franchise etc..) they
pretty much always use them. It means also the don't have to employ
real estate personel.

Second, companies rarely buy raw land, they buy/lease buildings. They
are not developers. When you have it approved then talk to them.

You can call them and ask who they use in your area to look for
properties as most who specialize in this know all the players.

Loopnet is where you can post it online. Good luck