Pantone Colours are spot colours. You get Pantone swatch books as reference guides to the colours you can use in a print job. As an example, I deal with a local travel agency whose letterheads are in Pantone colours 032 and Reflex Blue... which makes the thing a 2 colour job. Spot colours are basically set colours that are not made up of CMYK when they go to press, and are either used if a client wants a 1-3 colour job (ofetn to save money, as metal plates are produced for the press), or add a 5th colour, usually metallic or florescent ink to a 4 colour (CMYK) job on a lithograph press (such as a Komori).
If you are creating work for print, it might be useful (if you're freelancing) to pick up a Pantone Solid Coated and Uncoated swatch book... they can be pretty pricey, but are worth if in order to give you a true representation of how the ink will look on the final job, as I'm sure you are aware, what you see on screen is NOT the same colour as you get from a laser printer, desk jet, or indeed a lithograph press.