Don't threadomance old threads! Start a new thread instead. Anyway to answer your question:
IDE data cable (ribbon) vs SATA data cable (red):
http://www.ixbt.com/short/2k2-07/ser..._vs_ata133.jpg
"twisted" IDE cable ("Belkin" I think? notice the connector is still wide):
https://www.totalofficesupplies.co.u...ges/714978.jpg
To make the drive slave you have to set the jumpers properly. If you look at the back of the drive you'll see something like this:
http://support.wdc.com/images/drives...rs/jumpers.gif
(example only! not the same for all drives!)
Nowadays most drives have the jumper settings printed on the sticker but if you don't see the diagram, search for the drive model number on the manufacturer's site.
3) part 1 just plug in the drives - one master, one slave.
I'm not sure for 3) part 2. Don't know if it'd be bootable from XP (which would be D: if it were slave - at least if set up the "old" way), but maybe with BCD you can now configure drive letters independently of their position on the IDE channels. I have no experience with this. Just ask around or google for how to use easybcd or vista diskpart.
Note: you probably won't be able to boot from XP anyway unless the old computer had the exact same hardware as your new: you'll likely get a BSOD as you have different drivers and a different HAL.