I also got Crusader Kings II (the one exception to my indie purchases) but I just haven't been able to get into it, unfortunately.
About Crusader Kings II.. the best way to learn how to play it is to read/watch some LPs of it, to understand the mechanics, ways to play it, and the interface.
I'd suggest this
Something Awful LP or this
PC Gamer LP. There's also quite a few Youtube let's Play, though I don't have a link handy.
Just imagine that you are playing a ruler during the medieval age. Your goals are to foster a good heir, expand your dynasty, claim more lands, increase your King's opinion of you, and perhaps even become a King or Emperor yourself. How you do these things will vary from player to player, but it almost always makes for a truly epic story of love, war, intrigue, betrayal, and politics.
Oh, and there's also this: