chances are you havent set the pc to look at the cd-drive during boot-up. if you hit delete or a key like that during POST (the screen that comes up initially before any operating system kicks in), it should give you your motherboard's BIOS screen. the button u have to press does vary, so if del doesnt work try F1, F5, [tab] and so forth. once in there, in one of the sub-menu's u should see a boot sequence screen or something similar. make sure that the entry for your cd-drive is above your hard disk (altho u will probably want to put it after your floppy disk drive entry). it should then look at the cd-drive and see the Suse disk before the hard disk is examined.
good luck!!