To test the relay, with the battery charged up, take either a very heavy piece or wire or metal pliers with uninsulated handles and using the handle end, touch both of the large lugs on each side of the relay. If the relay is bad, it will now make a big spark and cause the starter to crank over. If it doesn't, either the battery is shot or the starter is bad.
To rule out the starter, hook jumper cables up to a car battery, hook the positive clamp onto the lug on the starter where the heavy cable attaches (make sure it doesn't touch the rest of the starter) and then touch the negative clamp to the bike frame. If the starter is good, it'll crank over. If not, bad starter.