Airspeed indicator from FS2004 Xsim and Arduino

Hi all, never used a forum of any kind before so sorry if I'm doing this all wrong. I bought an Arduino Duemilanove to learn somthing about programing and want to build a set of hardware aircraft instruments to practice instrument flying. I have a pilot's licence and this would allow me to practice and play far more cheaply. I am an electrical/mechanical maintenance engineer in real life so I can build just about anything but I know 'diddly' about computers. What I would like is a real idiot's step by step guide to set up just one instrument, rev counter or airspeed indicator either one would do. I could then build on that knowing that any problems would be either my own code or the hardware I have built.