With SATA you dont have to worry about that. If the IDE HDD is a WD then it should be set as cable select but if its any other brand then it should be set as master.
If your installing XP on the SATA, your gonna need an SATA driver before hand, so its always good to slap that on a floppy and then when the instalation screen first comes up, it will say press F6 to install a 3rd party RAID or SCSI adapter - Thats what you want to do, then it will seek the floppy and install the driver, at which point you can set it up on any one of the HDD's