sister natasha very good question.
i would suggest,if u have the time to read then please read the holy quran with the translation and meaning, with context.the holy quran itself is capable to clear all the doubts that a human beings possibly can have.
after that the most authentic is the sahih hadeeth.i.e sahih al buhari.
and as to ur question,why would a bad one be written,for that i can only say,all the good and famous have critics. right ?