I've come to find databases indispensable for all kinds of things. Unfortunately, over the past couple days I've encountered one of the big problems with using them: if you don't design them well from the start, then when you try to transfer existing data into a better-designed database, it takes a lot of work.
So let this be a lesson to you (or at least to me): learn about the principles of good database design before you create a database. Yes, that means it'll take longer to get it in place, but you'll be a lot happier further down the road.
Of course, I still only know the basics of good database design. It's possible that in another couple years, I'll have to go through a similarly rough switchover to a better design. But I think it'll be a lot easier next time; the new design may not be perfect, but at least it doesn't throw everything together in one huge table.