Publish Ruby Rails Site

Capistrano is the way to go, but it can be a little complicated to
manage at first, but you should stick to it.

Many Rails oriented hosting companies have recipes to use Capistrano
with their setup, you should ask your hosting for such help.

This search could be a starting point:
http://www.google.com/search?q=capistrano+deployment&hl=en&lr=&client=firefox&rls=org.mozilla:en-US:unofficial&hs=xgM&start=10&sa=N