On the switch, that can connect from a pin to ground. The internal pullup is used to hold the pin High when the switch is open, and the switch connects the pin to ground when closed. No other resistors are needed.
Many people writing examples seem to think it's wrong for an input pin to go from HIGH to LOW when you push a button. They insist on adding a pull-down resistor (to make the pin LOW when the switch is open) and a switch between the pin and +5V (to make the pin HIGH when the button is pressed). As CrossRoads says you can avoid the external pull-down resistor buy reversing the action of the button and using the internal pull-up resistor.
In answer to another question: Yes, you could use 3.3V instead of 5V for the switch. The voltage is high enough to register as HIGH on a 5V input. The only advantage is that the external pull-down resistor will use 0.33 milliwatts instead of 0.5 milliwatts while the button is pressed. Not a significant advantage.