I'd start off buying paying all my immediate families debt, and make sure they all live comfortably.
After that I'd buy myself a nice, 3 maybe 4 bedroom house, with a 2 or 3 car garage.
Build a decent sized shop just to work on my race quads in.
Buy 4-5 KTM 450XC's to build for GNCC/OMA/Whatever other series I decide to run.
Buy a 2003-2004 Cobra.
Put some away in an account for my future children's college funds.
Put away a few 100k in an account for myself.
Invest the rest.