Well, the easiest way is to let the Migration Assistant do it for you. Since you'll probably want to have the data from your old drive available, install the original drive in a mini Firewire case. I installed Tiger on my new drive from the DVD install disk (never hurts to have a known good clean install), and after startup used the Migration Assistant to pull all my old programs and settings from the original drive. Worked great, although I did have to upgdate a few programs since I was going from OS 10.3.9 to OS 10.4. You can keep the original drive as a backup, and if it's in a firewire case, you can boot from it as well.I would love to know how you guys transfered the OS and files before installation.
A highly recommended upgrade, especially since the 100 GByte Hitachis are now available.