Because the only purpose of the Classic environment is to run Classic applications, you need to know how to install and work with those applications.
Using Classic applications is very similar to using an application under previous versions of the Mac OS. Installing Classic applications can be a bit trickier, however.
You have two general options when installing a Classic application on your Mac OS X machine: You can install the application under Mac OS X or you can restart in Mac OS 9.2 and install the application as you normally would.
Installing Classic applications under Mac OS X is easier because you don't have to restart the machine in Mac OS 9.2, install the application, ...