Cataloging my Library.

I've played around with this idea before, but have never been able to justify the work. I have an odd tactile memory with things in my apartment: as long as I was the one to put something in its' current resting place, I know exactly where it is at any point in time. This, of course, includes my books. I don't have to hunt for a book, should I want to reference a passage, or wonder which stack on the floor of my closet a book is in. (I also never lose my keys.)

My friend, Gabe's apartment burned all the way down this weekend and he was faced with the awful scenario of, 'Ten seconds of snatch-and-grab, what should I take?' I, like Gabe, have good renters insurance, but seeing all he is going through may be impetus to sit down and account for all my books--some of which are rare, and pricey--should such a calamity befall me.

So since I'm going to be taking inventory and re-addressing the records, I might as well not half-ass the job and formally organize my meager book collection. Anyone done this before? What's the best method and how do I start?