Orion has been running LDraw.org for a long time (over 15 years at the time of this writing). While he does not intend to step down from that role anytime soon, this article is intended to get any future admin up and running should he be hit by a bus or something silly like that.
LDraw.org Key Data
You can access the server via SSH or SFTP. SSH access is more powerful. All web files reside in the ~/ldraw.org folder. The logs are in the ~/logs folders. There's a lot of other stuff in the home folder but most of it doesn't need to be touched unless you know what you are doing.
Inside of ~/ldraw.org are many folders. Most of these are not web facing.