" Can a DVD Rom be connected via another Ide cable straight to the Ide2 socket and be set to Master?"
"Or should the two disc drives be on the same Ide cable and be connected to Ide2 socket.With CDRW as master on the end of the cable and the DVDROM in the middle of the cable and set to slave.Thus leaving the HD on its own cable and connected to Ide1 socket."
You can also use that configuration if you wish.
"When this is all connected dod I just turn on the PC and it will find the new drives without me doing anything else?"
If the bios is set to auto, then yes. Don't forget to install the dvd software you get with the drive.