That is an interesting twist that I have not heard. Most people believe that Palpatin just discovered the Sith teachings and learned from that, but how does one learn the Force from a book? The only problem is that the Jedi should recognize Palpatine seeing as how he is in the political arena for quite some time.
Well maybe he did discover the teaching of the Sith, but maybe he just started out as power-hungry and the darkside recognized this and "took him" (for lack of a better term.) The darkside would seem to feed those who seek bigger and stronger power and pollute them in the process. In the ROTJ novel, in the throne room at the end, Vader is thinking "His boy was powerful, stronger than he'd imagined. And still pliable. Not lost yet--either to the sickening, weakly side of the Force, that had to beg for everything it received; or to the Emporer, who feared Luke with reason." To use the old quote to describe Sidious, "Power corrupts. And absolute power corrupts absolutely."