Read this Microsoft Word document I made for people just like you
http://forum.arcadecontrols.com/index.php?topic=56010.0It is the "Mala Stup How To" document but it includes a very detailed description of Virtual Pinball since I know setting that up could be daunting for some people at first look, although it is really quite easy.
In the first pages you can learn how to set up some directories including virtual pinball, but the real stuff you will then want to read is the "Virtual Pinball" section on page 13 .
It is pretty much a step by step to get it working. Not hard at all ..... just very detailed so there are a few pages to read through.
Also, last time I heard there might be some automatic installer which should install everything you need ...... but I am not sure what that is ...and I have never used it (if it even still exists ... dont know). You would have to ask around the Visual Pinball forums to know more. Now that said, I still prefer my way since this way you will understand exactly what it all means and where all the files live ...... kind of easy really.
Let me know if you have any problems. I have not looked into Visual Pinball for quite some time now, but I should be able to help you figure stuff out if you get stuck.