On thier website it says negitive,low, mid, high offset......what does this all mean...:)

those are the offsets that their wheels are offered in.
its a bit confusing if you ask me because most wheel choice only comes in 1 or 2 offsets.

the negative = stick out from body
low = tucked in a bit
mid = dunno
zero = depends on rim width but usually sticks out a bit

Wheel / tire size calculator / comparer - RIMS-N-TIRES (http://www.rims-n-tires.com/rt_specs.jsp)

play around there with offsets