Thanks MRQ,
My first post in months. I have an update actually. One of my rim is actually new....hahaha. A little sliding acident and had to replace the rear right. Spent about 520 for the rim and a new set of tires for about 600. Some cosmetic damage but nothing major. Could have bout a new set of rims and tires for that price but these look so good. While on the tow truck, everyone was looking at the car. How embarassing.
To semi-charmed, it would take me really long to answer you but I found this instead. If you are still confuse just post another msg. In short more negative offset means the rim will sit more outside the fender, you will need a wide body kit with this setup. More positive means the rim will sit more inside the fender
http://www.rsracing.com/tech-wheel.html