The reason you keep blowing circuits is as follows. Green, bare copper, or aluminum on the device are the only places the ground goes period. Groups of whites never go on to any switches in this scenario. They are know as neutrals which return to the panel-board to complete the circuit 60 times a second. The odd or different color screw is for the Hot (Power) or the Switch leg which goes up to the light fixture. The other 2 single wires that are red, black, or white (which should be taped as black by code are the travelers or dummies). It does not matter whatsoever which remaining terminals the travelers get connected to. Hope this helps all of you. It's a simple 3 way meaning three terminals on the switch and the capability of controlling a fixture from 2 locations. If the light is controlled at 3 or more locations then a 4-way switch comes into the equation. Please consult a professional licensed and experienced electrician if you are unsure of what you are doing. Invest in a voltage tester as well. Happy to Year!