How do you know the battery is ok, how has it been tested?
When you turn the key, do you hear a click or nothing at all? If there is no click, it sounds like the solenoid. There should be a spade connector with a thinnish +ve trigger - make sure it is tight. If it is and still no joy, then use a small piece of wire and short the +ve feed from the battery to the spade, then post back.
That will at least rule out the solenoid / ign switch.