http://img.photobucket.com/albums/v2..._n_fl/rear.jpg
Not a great reveiling pic, but you can get a somewhat idea. Mine are 18x7.5
Negative offset wheels are like deep dish wheels where the lip is very pronounced. Stock is 60mm and mine are 42mm so i have about a 1.5" lip on my wheels. I believe the lower the number the more negative offset you get.