We've been saving our seed packets & plastic baggies in an old floppy disc holder, but just grew out of it. Now, we keep all our seeds in a draw in my office (the whole drawer is seeds)
I sort seeds by family, height, days to maturity, etc.
Working on putting all of the info into an excel spreadsheet, so I can have a greater ability to plan the next seasons & successive plantings. This is a major undertaking, but I'll have a database of all the seeds I use and when I save & sell them, it's easier to populate the seed labels if everything's already typed out! Hopefully, this will give me a really easy way to pull up what I should be planting at any given time. We'll see!
Here in North Texas, Zone 8, we can grow almost all year long. I am DETERMINED to figure out a solid planting schedule to adopt & go by, always having many things ready to harvest & eat at all times. Planning is the hardest thing for me! I've ready The Market Gardener & am now reading the Urban Farmer and there's a lot of great info, BUT, the regions are totally off...
Good luck! Will be watching this thread for other peoples' processes!