THE PILOT REPORTED THAT WHEN HE WAS CLEARED FOR TAKEOFF BY THE CONTROL TOWER. HE WAS TOLD THAT THE WIND WAS 320 DEGREES AT 20 KNOTS. HE STATED THAT DURING THE TAKEOFF ROLL, THE AIRCRAFT VEERED LEFT. HE TOOK CORRECTIVE ACTION BY APPLYING RIGHT AILERON AND RIGHT RUDDER, BUT HE WAS UNSUCCESSFUL. THE AIRCRAFT WENT OFF THE LEFT SIDE OF THE RUNWAY WHERE IT STRUCK A TAXIWAY SIGN. THE PILOT STATED THAT THE ACCIDENT COULD HAVE BEEN PREVENTED IF HE HAD MORE INSTRUCTION AND PRACTICE IN CROSSWIND AND GUST CONDITIONS.