At a minimum, you would want to do the full rocker panel (up to the body line below the SRT-10), the lower half of the rear bumper cover, and the full front bumper and first 18" of the hood and front fender.
If you buy a high-end product, the clear bra is basically invisible. If you really want it invisible and aren't budget limited, then you would do the entire hood and entire front fenders. Today with high end cars that actually get driven (Ferrari, Porsche, etc), it is very common for them to have almost the whole car clear-bra'd for protection.
As far as doing it yourself, if you are patient and good at DIY projects then it's possible for you to do simple areas such as the rocker panels to protect against the sandblasting, but do not attempt to do the front bumper yourself. The material is very expensive and if you don't know what you are doing it will turn out horrible.
If you want to get more familiar with the material and process, check out this link. I have done a lot of research into this subject and this is one of, if not the best, product on the market. If you go to their support section, you can view the "how-to" guide to get a basic understanding of the process. It's essentially like applying a giant cell phone screen protector.
http://www.xpel.com/products/xpel_ultimate_paint_protection_film.asp
