well, i suggest start learning c++ concepts. u can find some really good tutorials on the internet just by using google.com (
www.programmersheaven.com is also real good). you can also buy a book and learn that way. then, once u feel u have a good enough grasp on that, start learning some windows programming. then, from there, i suggest learning directinput, directsound, directdraw, and after all that, if u like u can start learning how to program in a specific API, such as directX or openGL. but, u must be patient. it will take u quite some time, and hard work as well, to build ur skills to the point where u will be able to emulate any console with success. As long as u stick with it, and don't give up, and once again, BE PATIENT, u will eventually start making progress toward and emulator.
oh yah, don't try to out do yourself. set practical goals, and when u reach them, set new goals that are a little more challenging, but still practical