If you mean real carbon fibre, you can buy 2x2 twill weave fabric from eBay & then buy epoxy resin, or you can buy a kit like this one:
http://www.carbonmods.co.uk/Products/Carbon-Fibre-Skinning-Starter-Kit---Large__CMCFSK1000.aspx
I've just skinned my RS4 engine bay side panel & it's been a bit of a learning curve. Something I didn't realise is that if you add too much hardener to epoxy resin, it doesn't cure. I've been having problems with the epoxy, the actual carbon fibre fabric is pretty easy to use! I added too much hardener - I thought that as the weather's been cold, I'd add more to hurry up the cure process... in the end I flatted it all back & applied again.
You can use polyester resin, though epoxy is meant to be better for carbon fibre use.