If your bike is old enough that the fuel pump is located outside the tank and/or non-electric -- you'll need a shut off valve that's mounted on the handlebars and actuated without having your hands come off the bars. Usually it's a Pingel or something that has a bellcrank-type lever attached to a cable that goes to the valve and is actuated by the rider's thumb. This goes for both fuel classes (Gas and Fuel).
If your pump is electric and does shut off when you throw the master kill switch (these days usually mounted for right thumb actuation) then you need nothing further for gas class. For fuel class I think (not positive, though) that you'll still need the cable or something-actuated lever switch for your thumb to move. If you're running nitrous cutting off power to the solenoid is enough. If using nitrous, though, make sure to have an easy to find, easy to read label so the safety workers can find the shutoff valve immediately upon reaching the bike after an "incident". The inspectors will gladly tell you if the shutoff valve isn't easy enough to find.