I will c/p from a post I made to someone else to make it easier on me...
Go to each site, put in your search options, which would be land, then put a price in. You then want to make a profile at each site, saing what you find, saving the search also. This will get you emails as soon as new properties are listed or have price changes. I've found the sites to be reliable, all updated within 24 hours if not less.
See if you can find a copy of homes & Land magazine, I picked my copy up at the food store. Once you get a feel for the market and what's out there, you might think to find an agent. The way i picked mine when I was looking was I signed up at her site, she was great with emails & not pushy. We devolped a "relationship" via email before I went looking with her.
Major real estate sites
Realtor.com main search - click advanced search to get more options
Caldwell Banker
Century 21
ReMax NJ
Exit Reality main site (broken link)
Weichert
Garden State MLS
Homes & Land
Homes.com
Land & Farm NJ
For Sale By Owner