I’m currently working on a series of tutorials on car modeling. The first tutorial I’ve written up is modeling tires. There are a ton of way sot do it…but I’ve found this method to be easy and forgiving
http://dragon-realm.net/~morokiane/tire.htm
the source for the image I use is
http://dragon-realm.net/~morokiane/real_tire_2.jpg
and lastly a good source for tread
http://www.tirerack.com/