If your record collection is growing, there comes an inevitable moment when you realize that some organization is necessary. Having a good place to store your records is the key to keeping your records in good playing condition. Warped records are the enemy.
Probably the best method to store records, if you're handy, is to make record cases with wood or some other material. It's the vinyl equivalent of a bookcase. If your collection is modest, you can get by with a couple of shelves. If you're a serious collector, then the shelves may go from floor to ceiling.
For those who are not handy in the wood shop, there are alternatives that can be purchased. If you've got the idea to invest some money and want something nice, you could look at something like this Boltz two-shelf LP rack in metal or this
MusicDirect two-shelf maple LP rack in wood and metal. Those two racks will set you back $449 or $350 respectively. That's a lot for a fairly modest amount of record storage.
Finding affordable storage for records is getting harder these days. Records are a niche product, and there simply aren't as many collectors out there as there used to be. It takes a bit of digging, but cheaper solutions do exist. The best of the cheaper solutions is an enhanced plastic crate. At one time it was easy to find milk crate-style plastic crates. Most discount stores carried them. The problem with milk crates is that they weren't tall enough, and records stuck in the back were in a position to warp if enough pressure was exerted on them.
The Container Store, a chain store with outlets in most major metropolitan areas, has the perfect solution. They have the Supreme Crate. The Supreme Crate comes only in black, and it's the perfect size for storing records. It's taller than a standard milk crate (The Container Store also sells those as well), and does a better job of protecting their precious cargo.
The crates run $14.99 each, which is definitely more than similar crates in the '80s, but you won't find better plastic crates than these. Your best bet is to find these at a Container Store location in your city. Otherwise, you can order them from the website, but you'll have to pay shipping, which is a little steep.
Full Disclosure: I am writing about these crates simply because I think they're great. I was not asked or paid to write this review.
Update (18 Nov 2009): When I first bought supreme crates from The Container Store, they were $12.99. At the time this blog entry was written though, they had gone up to $14.99. But shortly after that, the price returned to the $12.99 level and has stayed there. For now. Also, it looks like the URL changed for the Supreme Crate, and I've fixed that. The MusicDirect maple LP rack is no longer available.
Update (30 Aug 2010): The Supreme Crate is what I've stuck with, and it works well. I've stacked them two high and am currently using eight of them. Here's a photo of my collection: