We've done this the last two years and it has worked well for us. It's been most of a year since I did this so the details are a little fuzzy.
You need to get a Cypress Carrier board from either AndyMark or eStop to make connecting switches and potentiometers much easier.
First you need to download the proper firmware to the Cypress board. The instructions are in the 2012 control system quickstart
http://www.usfirst.org/sites/default...ystem_RevA.pdf starting on page 39.
Once you've run through the instructions and your driver station sees the board you can start by wiring up a switch. The digital inputs have pullups so you ground the input to get a low. Check on the driver station enhanced i/o to make sure that flipping the switch changes the input.
Look in WPI Robotics Library -> Driver Station -> Enhanced IO for the vi's that will get the digital and analog input arrays. You can get the input you need out of the array.
This is the quick and dirty version since I don't know how familiar you are with the board or electronics in general. Ask if you have any questions.