It's not hard at all. You're going to want BootCD and just open it up and do it asks you a few questions, makes the CD image, lets you choose what apps to include, etc. Then you simply use Disk Utility to burn the newly created disk image to a CD ("Images" menu-->"Burn")
It says that it's not "supported" but that sometimes it works. I used a Panther computer to make one and it worked, maybe I'll try making a Tiger one later.