Speaking as a professional photographer regarding storage/organization...

Simply keeping images on a computer is too risky and it would fill up too fast (psd files easily get up to 40MB each). In fact, I store nothing on my computer - rather I keep files on a portable hard drive which I can carry with me and use with any computer (I fill up a 500GB LaCie drive every 7-8 months). I also back up each hard drive completely to another hard drive every so often and upload select images to a cloud server. It's important to spread things out and have multiple copies so even losing an entire hard drive is no big deal because I've backed it up.

I use Lightroom to catalog and keyword images, and start a new catalog with each new hard drive. Naming every image sequentially is useless because I shoot so many images it would be impossible to track down a shot later if it only had a number. With Lightroom, I create collections and add keywords so it takes seconds to find an image by search. Plus, Lightroom saves the edit history for every image on one master file so I can go from computer to computer and still have an updated catalog.