Replying to Origins of biblical scripture

I'm not very well educated in traditional western religions (i.e. christianity), but from what I understand, great importance is placed in various divine scriptures which speak the words of God, prophecies of Gods son, etc... (excuse me if my details are inaccurate, that isn't of importance here)

what I was wondering was what are the origins of these divine scriptures exactly? and why are they taken as the word of God rather than the word of a very crafty author?

I don't want to start any debates here... I just want to know why these scriptures are taken as seriously as they are?

(i'm writting an essay, I dont plan on plagerizing anyone, I just want to hear a few ideas as a starting-point for my research)