There are several free scheduling programs/services online, but When is Good, saved my life and a LOT of paper! It's simple, straightforward and just works.
When is Good allows you to develop and event and send out a call to participants via e-mail. They respond, and the computer finds the "times in common" for you and the group! And you see it as a chart. I know! Super.
Here is an example of what an account looks like:
Watch a video about the program works here.