Do you have an SCSI cable already?
If so connect it to your EMU and the other end to the back of the CD Drive
Now if your CD drive is anything like mine it'll have a jumper switch that says "Termination" Switch this to on.
It should also have another switch with various numbers listed, these will be the device IDs
The best bet is to try turning on the CD drive and then your EMU (with both connected) and see if it mounts, if it doesn't mount turn both off and try setting the CD drive to another ID number.
Repeat until it mounts
Also make sure you give them a good few minutes between switching on and off again.
I had alot of trouble getting mine to mount at first (theres a post on here somewhere) In the end it turned out i had a dodgy cable, tried a new cable (99p off ebay) and it worked first time