For the most part this answer agrees with Jadasc (and apologize if this should be a comment and not an answer).
With White Wolf in general, the only way to learn the canon plot is to literally read everything in every book you can get a hand on. It sounds like an absurd answer, and for the most part it is. Most of the time, you just pick and choose what aspects you want to include in the game proper, find what sources you can and read them until you're happy with what you know. Feel free to read at least the blurbs on other aspects to see what may be analogous to your core theme. Otherwise, players are probably going to read up on the things in relation to their characters, and when they do something involving that they will often tell you because they want it to be meaningful that they did their homework.
(At this point I have assumed the presence of many a downvote for saying "let the players do the work you don't want to".)
What I mean, is that when you have entire universes you may or may not be including, a lot of it will end up being retroactive to the plot. If you're just doing Requiem, there isn't much need to read up on Forsaken, Awakening, or the Fallen. When it comes down to it, all of those books are part of the same universe and technically all mesh together.
Short version? WoD is a grab bag of plot.