Shower Help! PLEASE!!

I tried replacing my showerhead faucet combo and took it off. When I tried taking it off, I realized that it was the original copper plumbing that came with the house and did not match up to any of the new shower combos. I had to rip out the plastic liner, along with some of the drywall. Now that I have done that I would like to rip out the all of the plastic liners and replace it with tile. I need to know 1) Should I rip out all of the drywall and replace it with cement board? 2) How do I tile the shower correctly without making a huge mess and damaging the shower.
Any help would be appreciated.
-Thanks

You may want to pop over to John Bridge for that

http://www.johnbridge.com/vbulletin/index.php

While you have the backer board out, it's a good time to replace the shower valve, new ones should be pressure or temperature balanced.

Well, you have backed yourself into quite a project, but it is doable.

Tile must NOT be put over drywall in a shower. Cement board is the traditional prodcut, but must be put up with the proper moisture barrier behind it , taped joints, overlap the tub flange, etc. Do a LOT of homework before you start this project.

Since you are opened up, have you considered having a plumber properly install a shower valve? It sounds like you are a little light on DIY skills, and that valve needs to be good for 20+ years after you go to all the trouble of putting new tile up. How about posting a pic of what you have?