Hi Greg,
Welcome to the wonderfull world of Arduino. As you are new I would advice spent a evening or two in the tutorial section and work through the samples. You will learn a lot there what is possible and what not.
Furthermore go through the discussions in this subsection and see if there are some that sounds familiar.
Finally the playground may contain interesting articles you can learn from e.g. - Arduino Playground - SingleServoExample -
HOpe this helps to get you started, in the meanwhile if there are questions just ask! Astronomy related items are discussed here too e.g. - Arduino Forum -