It is included in Mac OS X (as of Leopard), although in reality almost all deployments target some Linux distro and any development you might do on your Mac will end up being with a more up-to-date version that you install yourself.
Older articles (not up-to-date)
- "Capistrano: Automating Application Deployment": http://manuals.rubyonrails.com/read/book/17
- "Really Getting Started in Rails": http://www.slash7.com/articles/2005/01/24/really-getting-started-in-rails
- "How to show Google’s Web Accelerator the door in Rails": http://david.backpackit.com/pub/37983
- "Skinny Controller, Fat Model", an excellent article that argues for and uses code examples to demonstrate keeping code out of views, simplifying controllers, and letting models do the heavy lifting in the interests of better readability, maintainability and correctness: http://weblog.jamisbuck.org/2006/10/18/skinny-controller-fat-model