Need to Re-install Leopard - Clean Install This Time

Help. I upgraded to Leopard the simple way and it's caused nothing but problems ever since. Programs lock up .. constantly. Someone suggested doing a clean install. My question is.. now that I've installed it, how do I go about putting the genie back in the box? Do I uninstall first? If so, how?

When going through the setup, does it say "clean install" or is that something you need to know to look out for? Sorry for being so ignorant. It took me 7 tries to boot up successfully tonight; it's time. I need a "dummies" version.

Thanks for your help, in advance...

Boot up using the disk. In the steps that follow, there will a button "Customise" (I think it's the third step). Just make sure you select "Erase and Install" instead of "Upgrade".