First, make sure the transmission is in Park. On the starter solenoid, use a heavy screwdriver to jump across the battery terminal and the small terminal. The starter should crank the engine. If it doesn't, jump across the two large terminals. The starter should spin, but not crank the engine, because the drive pinion won't be engaged with the flywheel. If it still doesn't do anything, make sure the battery is charged and check the cable connections.
Please post back and let us know what you find out.