The problem with attempting to deal with the Magisterium of the Church is that it is so vast, that the only way to do it is as one would eat an elephant: one piece at a time. I propose to do just that. Today's contribution represents just the first course - more will follow.
As the people who insist we follow the Magisterium often also refer us to the Bible, I thought it would be helpful to begin with a look at what the Magisterium has to say about the interpretation of Scripture. Even this is a vast topic. One good starting point is to look at the useful report of the Pontifical Biblical Commission in 1993, "The Interpretation of the Bible in the Church" (which may be read in full at the excellent "Catholic Resources" website of Felix Just, SJ).