Check out RailsApps - https://github.com/RailsApps and http://railsapps.github.com/. It's a bunch of open source Rails 3.2 example apps and tutorials. I found it extremely useful when building my first applications.

Thanks Jaxon, This looks like a great place to start.

Not sure sepcifically about rails but I usually go to github and search for the keyword there. It shows me a list of all projects under that keyword and you can possibly filter through that to "watch" the ones you are interested in?

check out copycopter and bcms as well.

Honestly I'd say this depends on your goals - are you trying to learn? Or just make something (either answer is fine)? If the former, build. The latter, plug something in.

check out refinerycms