[Tweakhead]

You should:
1. Physically install the drive
2. Put the OSX Install CD in your drive and choose to install OSX. At this point your mac will boot from your OSX CD.
3. When the install menu appears go to one of the top menus and choose OSX Disk Utility.
4. Format your new drive as "Mac OS Extended (Journaled)"
5. Return to the install screen by quitting Disk Utility.
6. Install OSX to your newly formatted drive.
7. Download OSX 10.3.4 update from Apple. (Don't use automatic Software Update, as it will update you to 10.3.5)
8. Follow Digi's install instructions to the letter.

You can reboot from your OS9 drive by selecting it in "Apple Menu/System Preferences/Startup Disk" (OSX)

You can then reboot to your OSX drive by selecting it in "Apple Menu/Control Panels/Startup Disk" (OS9)

Or alternatively, you can hold "Option" during startup and you will get a blue screen with "Rescan/Hard Drives/Startup" icons.