What is the best way to catalogue your library if you're a book collector?

While on a short semi-vacation earlier this week, I bought a few new (to me, they're actually quite old) books. On the plane home, I got very excited at the prospect of reorganizing my library, which is pretty large for a personal one, I guess. We have two separate sets of bookshelves -- one on the ground floor in the living room, and one upstairs in the room I use for my office.

I've decided to go with a standard fiction / non-fiction filing system after debating numerous more fun or more complicated systems and plan to spend the weekend diligently alphabetizing all my books. I'm really excited about this.

However, I also want to make a catalogue of my books. I used to have a physical card catalogue but that is unruly and laughable at this point and at this scale. I know you can compile books you own in Goodreads, and Library Thing -- both of which I've used in the past. But, from an archiving perspective, I'm wondering if there's something better? Ideally I'd be able to use a barcode scanner for the books which have barcodes, and enter manually all of the others. I'd like whatever I use to be fairly sophisticated in this regard -- probably more than half of my books do NOT have barcodes, because I collect old books, mostly. I also really want there to be an app for Android available, so that when I'm at a junk store or whatever, I can access the catalogue, because I sometimes forget what I'm looking for and what I have.

For fun reference, I collect old Modern Library books, the new Penguin clothbound classics (the ones with the amazing Coralie Bickford-Smith-designed covers!), Sweet Valley High books, Modern Library College Edition paperbacks, the Scribner Library paperbacks, and Nancy Drew (mostly the 70s versions, so groovy) books. I also collect every version of Jane Eyre I can find. I don't have vast collections of any of these because I don't really shop that much and am not really a collector by nature, but over the years I've amassed a nice amount.