Some time ago there was site with a lot of similar projects on the site mp3projects.com. From some reason this site is be unvailable now.
Fortunattely I have downloaded schematic for connecting a PIC with CD-Rom. I hope that will be of some help to you.
As a first I suggest you to read FAT file specification which you can download from: **broken link removed**
As a second I warmly suggest you to download program for view of the hard disk locations. My choice was winhex: http://www.winhex.com