The pushbutton switches are wired incorrectly. They will have undefined "floating" inputs when they are open. I hope the "tuts" didn't do it this way..
You need internal or external resistors with the switches. The easiest way, is to enable the internal pull up resistors using the INPUT_PULLUP option, connect the other end of the switches to ground instead of 5V, and invert the logic in the program to look for a LOW state with an active switch.
Look at the DigitalInputPullup example that ships with the Arduino IDE.