Camera ready artwork is printed in very high quality, and printed as CMYK seperations. Typically, you'll print artwork on the brightest white paper you can buy, and you'll print it on a high quality laser printer. If you don't have a laser printer, borrow one, or your prints are gonig to look like crap.
You will have 4 plates (well, assuminbg it's full color). One each For Cyan, Magenta, Yellow and Black.
When the printshop gets your artwork, they'll put it in front of a camera, and shoot film positives from it. anywhere that was white on the paer is clear on the film, and anywhere that was black on the paper is black on the film. There are NO other colors besides white and black on the film, not even grays.
Anyway, after they have he film, they use it to photoetch metal plates that will be raised where the film was black, and etched away wherever the film was white. Then, these plates are inked, (one plate for each color) and stamped down on the paper on top of each other, giving you a full color image.
I worked in a graphic design studio doing work for print for 2 years, PM me if you have any more questions.