The flight was sequenced behind a Malibu for landing on runway 03, and the pilot was instructed to allow the Malibu ample space for the landing. About 1/2 mile from touchdown the pilot was instructed to go around to allow the Malibu time to clear runway 03. The pilot started a go around and reported a dual engine malfunction during the climbout. The flight was cleared to land on any runway. As the pilot turned left toward RWY 21, the aircraft crashed into a small grove of trees 1100 feet left of the extended center line for runway 21. Examination of the airplane revealed that the pilot had placed the fuel selector valves in the AUX position. A placard on the fuel selector valve assembly stated 'USE AUX TANKS AND CROSS FEED FOR LEVEL FLIGHT ONLY.' Subsequent examinations of the airframe and power plants failed to disclose any mechanical or system malfunction. During the post accident examination, the right engine started and operated, on the airframe, with the existing fuel and supportive systems.