[dlavery]

Since you say you are completely new to sensor systems, let's start off with the ultimate in simplicity and go from there. An extremely simple (and it turns out, very effective and incredibly inexpensive) solution works like this:

step 1: Attach two simple bump sensors to the front corners of your robot. These "bump sensors" can be simple microswitches that are normally open (i.e. when connected to the digital I/O ports on the RC, they provide a "0" indication), and close when they make contact with some object (and thereby change the state of the digital input to "1'").

step 2: Position the robot in the starting square closest to and facing the corner goal (i.e. as you stand at the center of the long edge of the field, facing the field, put your robot in the square to your right, and have it face the corner goal to your right). Then have the robot execute the following instructions:

step 3: Turn to the right until the bump sensor on the right front corner of the robot hits the edge of the field. This aligns the robot drive direction with the edge of the field, heading toward the corner goal.

step 4: Drive forward until BOTH sensors detect contact. This will indicate you have hit the player station wall. Stop driving.

step 5: Spew out the balls into the corner goal as fast as you can.

step 6: All done.

Once you get this simple sensor implementation nailed down and working, then you can start to get a little fancier. Ultrasonic sensors will allow you to do fundamentally the same thing that the bump sensors do. The only difference is that instead of just telling you when you have actually made contact something by bumping into it, the ultrasonic sensors can tell you the approximate range to an object as you begin to get close to it. So you can slow down and smoothly stop your robot just before it reaches the end wall, instead of running into it at full speed and then figuring out "ohh! there is a wall there!" And yes, using the ultrasonic sensors from a VEX kit is permissible under the current rules.