How do you install Danbooru on a CentOS webhost?

You'll just have to try and work it through. I got Danbooru deployed on Gentoo Linux, and there were no instructions for that platform.

I would recommend going through this thread:
http://danbooru.donmai.us/forum/show/27530

And checking the the BASH installation script that MasterAnu made. It will *NOT* work on your platform, but it makes an excellent guide as to which packages and software you need (it greatly helped me figure-out Danbooru's dependencies on Gentoo). Try and see if you could possibly find some CentOS/yum equivalents of those packages, and install them.

That being said, if you're not comfortable with Linux, the command line, or database administration, you probably shouldn't try deploying Danbooru just yet -- it's not a "download and deploy" solution like most software is.

Again, I'd recommend checking-out that script I was talking earlier, and using that as a basis to try and find the packages/software that Danbooru depends on.

And if I was on CentOS right now (or a Debian/Fedora-based distro), I'd be able to help you out a lot more (maybe even get ya' an installation script). But I'm not too acquainted with those distros, unfortunately.

Good luck, though.

Edit: Also, I think I just realized you were talking about your host -- not an actual machine you own.

Simply put, if that's the case, you're not going to be able to get Danbooru to work on that. Danbooru just has too many dependencies, and there's a high chance that your host doesn't have all the software (or all the correctly versioned software) that Danbooru.

I tried to deploy Danbooru once on my host... but the effort was completely futile. You'll have to have access to your own server/machine if you want to get Danbooru up-and-running.

Sorry to put it so harshly, but that's the truth. You can still try, though.