All of what the above said, very good tip from PRSPlaya, but i have played around with a few fenders and i haven't found what i would call a ozzy distortion sound, but i have played around with this-
http://www.musiciansfriend.com/product/DigiTech-DF7-Distortion-Factory-Modeling-Pedal?sku=150838
Its a great little pedal you will b able to get all the sounds you want out of this specialy if your looking for classic rock sounds, and some heavy tones.
you can get it for a good price on ebay.
Have fun finding your tone ;)