[BitTwiddler]

Here's how I've been telling our electronics team to wire up switches connected to the Driver Station digital inputs.
It shows how to hook it up when your switch has two terminals or three terminals.
Normal convention is that when a switch is in the "off" position, the signal line provides +5 volts and ground when "on" so you may see the opposite of what you expect in your programming but its usually easy to invert the sense of the switch.