Welcome to the forums. I agree with Pain and 69. If your battery is good, it's probably the solenoid or the starter, more than likely the solenoid. Try jumping the two posts on the solenoid with an old screwdriver. If it starts, the solenoid is likely bad. If it don't start, it's probably the starter. Try using jumper cables to send power directly from the battery to the starter. Hook the ground on the starter casing or the engine and hook the hot to the hot post on the starter.