FINAL FANTASY XIV Beta Test Application Site

All you need is an account and the updated client.

EDIT: Open beta's been postponed for now, but you can still get the client.

How to download patches the easier way:
1. Open the patcher. Patcher will get the necessary data for the patches.
2. As it's downloading the patches, close the patcher.

3a. Go to: "Documents/My Games/FINAL FANTASY XIV Beta Version/downloads/ffxiv-beta/[random]/metainfo"
3b. Open the torrent files in your favorite torrent client and download the patches.
-OR-
3. Use Megaupload. (faster)

4. Save the patch data in the "/ffxiv-beta/[random]/patch" directory. Make sure the "[random]" folder is the correct one for the patch.
5. Open the patcher and it will install the patches.
6. Wait for open beta to start.