Programming Sensors to Arduino

I am making a full size Skeeball game using an Arduino UNO, a Dell monitor to keep score, and 7 SainSmart HC-SR04 Ranging Detector Mod Distance Sensors that will go underneath the board with the 7 holes where the skeeballs get thrown into. On the backside of the board is where each sensor will sit so when the ball goes through the hole it detects it and sends it to the monitor adding a certain number of point depending on the hole it goes through. Never have I worked with sensors for an Arduino, any idea how to code it?

A sensor pointed at an unchanging hole is presumably a more or less fixed reading.
A ball passing through the sensors field should result in change in reading.
One option might be code that polled the string of sensors looking for changes in readings, and then acting when it found one.

You might like this:
http://www.ebay.com/itm/10-x-Ultrasonic-Module-HC-SR04-Distance-Measuring-Transducer-Sensor-for-Arduino-/130705106799?pt=LH_DefaultDomain_0&hash=item1e6ea1a76f

Some people might like lever switches to detect the balls.
http://www.ebay.com/itm/6-LOT-TEMCo-HEAVY-DUTY-15A-Micro-Limit-Switch-Long-Lever-Arm-SPDT-Snap-Action-/281125086074?pt=LH_DefaultDomain_0&hash=item41745c637a

Alright I will look into those! Thank you