Insert your Mac OS X disc and then power on the computer, once your hear the "bong" sound hold down the "c" key until it presents you with the Mac OS X language selection screen. From there it is pretty straightforward to install the OS 🙂
Go to the Utilities menu and open Disk Utility. Your drive should show up on the left. Click it and hit Erase then format with HFS+, journaling doesn't really matter. Format.
Load the OS X DVD as already said, and open Disk Utility. If this is a brand new drive you installed, most likely it has no partition scheme, so you will need to set a partition scheme before you can format it. To do this, follow the directions after opening Disk Utility:
After you complete the these steps, you can close Disk Utility and continue installing OS X.
Thank you everyone so much. I'm a first time Mac user with little knowledge of the OS besides basic functions so I was really stuck. Now I am happily running my laptop with 4 Gb RAM and a 500Gb HD! Thanks, and happy Mac-ing!