Id say picking up an exercise physiology book is prb a good place to start. I dont know your background and what you already know. But reading up on basic physiology will be helpful. Mcardle, Katch and Katch is the text book we used for pretty much all the physiology courses I ever took...
As for the more advanced stuff and performance nutrition stuff, Id say you gotta just research and read alot!.And dont just read the purpose and the conclusion, really try and grasp the information. If you do that Id say you would be on your way to becoming very knowledgeable..
Not sure if thats the kind of answer your were looking for, or if you were looking for actual articles and such. If your looking for articles, I suggest you roam this section of the forums because people post alot of links to different articles.
Hope I was some help.