Where can I get CruiseControl, and what do I need to run it?
You can download CruiseControl from http://cruisecontrol.sourceforge.net/. To run CruiseControl you will need Java, Ant, a Web server, and some kind of servlet engine, such as Tomcat.
Continuous integration sounds like a great idea, but it's a little daunting for me right now. Where can I start, today?
Start using a source control repository such as CVS, PVCS, or Microsoft Visual SourceSafe. Add all your project source and supporting libraries to source control. Then, work at building from source control on a clean or build machine. It's only a small step from here to full-blown build automation.