I tried reading it quite a few years ago, but I never made it all the way through. I checked it out from the library, but it was due before I could finish.
I keep on promising myself that one day, I'll get around to finishing it... Maybe after I graduate, I guess.
From what I remember of it, it's quite different from LOTR - to me, LOTR was like a very detailed bard's tale... A travelling journal, sort of.
I thought Silmarillion was definitely bible-ish, as Triumph said. It's a lot like a history book, but it gives a great deal of background to Middle Earth mythology.