Note: photos show a Stamp board, but concepts are the same for an Arduino board.
Here is how to connect a membrane type push button switch such as the one given out in ME2011. An alternate method is to solder to the switch legs. If soldering, pick two diagnonally opposite legs for the switch connections.
First straighten the legs of the switch with a pair of pliers.
Insert switch into the solderless breadboard. Note the orientation.
Make the connections. Any pin can be the input. For the ME2011 assignment, use Pin 3.
If the switch does not seem to be working, use a multi-meter to measure the voltage at the Arduino pin connection when you push the switch. The reading should be 5 V when the switch is not pressed and 0 V when the switch is pressed.