[Rails] File sharing site tutorial?

Welcome! If you haven't already, please do yourself an enormous favor and work all the way through Michael Hartl's Rails Tutorial. It's free to use on line, and there are for-pay screencasts and PDF materials, too. http://railstutorial.org

Then, have a look at http://ruby-toolbox.com, where you can find a bunch of categorized Gems and Engines for almost any sort of task. Paperclip is really good, well tested and mature. I also really like Dragonfly, but the best case for that one is any time you don't know up front how large you may want to show your images. It allows you to lazy-thumbnail to any dimension after the image has been uploaded and stored. Finally, there's also CarrierWave, which I've used once, and liked a lot. All of these allow you to use a cloud storage option, so you don't have to worry about your server filling up and 'sploding.

Walter

Thanks for the super informative post! I've done the very basics of
rails, and I'm honing my Ruby language skills at the moment (I've heard
it's a bad stereotype, that people learn RoR for before Ruby itself)

I'm guessing Amazon cloud is good cloud hosting for this sort of thing?

Sure, or EngineYard or Rackspace. Lots of clouds out there. If you're just getting started and testing it out, you cannot go wrong with Heroku. Deployment is as easy as a git-push. The starting price is free.

Walter