I don't know what information you need. I guess you need some project with MCU for control of CD-ROM.
1.If you want just simple player for CD tracks, project is very simple. You need little MCU and several external components.In this case decoding and D/A conversion will be done inside same CD-ROM. You will only do simple control of number track, play/pause/stop/eject.
2. If you need mp3 player you must use mp3 decoder chip or most complicate variant with software decoding (in case of software decoding mp3 you must use powerful controller like ARM...).
If you haven't enough experience the best way is simple copy some project from net. You have many project of this type. Just search like: control cdrom atapi avr pic... and you will find 1000 solutions.
Here is one:http://www.8051projects.info/blogs/post/A-Simple-8051-based-ATAPI-CDROM-audio-controller.aspx