This is how I keep my seeds organized. It's not rocket science, but it works. I got a large index card holder with the little alphabet tabs and I put my seed packets in.
If you want to be an overachiever, you can write the year you bought the seeds on the packet and you can keep a running list of seeds you're out of that you need to buy. But even if you don't want to be an overachiever, this is so much better than a drawer/counter/corner in your garage/basement/attic stuffed with packets of random seeds spilling out and reproducing with mouse poop to form mutant creatures that will eventually take over the world.