Could you please specify a bit as to the nature of your problem?
Classic should boot up when you open it. A little window should come up that says something like "Booting OS 9 from Macintosh HD." If you click the arrow in the window, you should see a OS 9 booting in a window. When the booting is done, the classic app is pretty useless. From now on, you can use the OS X desktop application to browse files, etc. If you then double-click on an OS 9 application, it should open up and work just as before.
(In fact, if classic isn't running, double-clicking an OS 9 app should open classic first.)
At what point in this process do you run into trouble?
If you describe exactly your problem, perhaps I or someone else can help you.