there are several ways to make a certain part look like it's made out of carbon fiber.
1st is obviously make it out of real carbon fiber. and there are two different types which are dry and wet carbon fiber. I believe dry carbon fiber parts are made by baking them (or heating them) to burn off excess epoxy (or resin or whatever the hell they use) after layers of carbon fiber and epoxy are applied to the mold, thus making them lighter and stronger in the process. Wet carbon fiber parts aren't baked so they are heavier.
another way is to use fiberglass instead of carbon fiber and then apply only one top layer of carbon fiber. most so called "carbon fiber" parts are made this way because it is cheaper (obviously because you are using less carbon fiber) and it looks like the entire part is made out of carbon fiber. (and i heard you can only make "wet" carbon fiber parts with this method because fiberglass will melt)
the last method is to make a part with whatever material you like, then apply a carbon-fiber patterned sticker. you can also paint it to give it carbon-fiber looks.

You can order many different types of carbon fiber fabrics fromhere. This is a very good website to buy various kinds of epoxy from.
Also this website has a very good selection of carbon-fiber patterned stickers made by 3M so you might want to look into it depending on what kind of parts you are trying to make.