When you tried to boot from the Tiger CD what happened?
Let us know
In that case we need to setup the drie and format it so you can select it as a destination.
Could you boot off the installation CD then go to the menu and start Disk Utility.
From the disk utility you should be able to see and format your new disk as HFS+
Once you have formatted the drive you should be able to reboot from the CD and install your OS.
Let us know if you have any issues
As you have the upgrade of Leopard we will first need to install Tiger then perform an upgrade to Leopard.
From Disk Utility Choose your drive then choose Partition.
Choose 1 partition and set it to the maximum size.
Once the partition is created format it and you should be good to go.
This guide from KenStone should help you through setting up the drive http://www.kenstone.net/fcp_homepage/partitioning_tiger.html
Let me know if you need more info.