Under the website for my course (1md3) there is a "Help" section.
http://www.cas.mcmaster.ca/~cs1md3/help/help.html
Here it has links to everything you need and also a very complete walkthrough.
I actually just got this working fully. The thing that I had trouble with was Vista Environmental Variables. Basically you have to tell windows where to look for java and the complier.
I had to change javac.exe to run into Compatability mode for the command prompt to be able to access it. It was a small glitch but still frustrating.
The Correct version of Java you need is listed on the help website along with the ACM file and a hello world example.
Enjoy