What's a good way to set up a development environment on OS X for ruby, rails, and git?

I'm going to start development on a web app using ruby, rails, probably either postgres or mysql, and most likely apache. I'll be using a git repository with the master repo on another server.

I've searched through stackoverflow and done some Googling... so here's what I have so far...

What are your opinions on what's described on this page?: http://robots.thoughtbot.com/post/159805668/2009-rubyists-guide-to-a-mac-os-x-development

What about this one?: http://www.buildingwebapps.com/articles/79197-setting-up-rails-on-leopard-mac

I don't need helping finding an editor, there's plenty out there (TextMate, TextWrangler, MacVim), but I do need help to make sure I'm setting things up correctly to code, build, and run the web app from my mac.

Here's a 开发者_如何学编程specific set of scenarios I could use some help on:

• Testing various versions of rails and/or ruby.
• Testing performance, vulnerabilities, monitoring queries, etc.
• Testing different versions of gems.
• Working on other projects on this same machine.

Neither of these articles mention rvm which is probably a "must have" for testing multiple versions of rails/ruby

These aren't really the things you should be worrying about at this point. Rails promotes rapid development. Until you actually launch the site SQLite/webrick will more than adequate for building the application.

I understand the desire to set things up perfectly before you start development, but I'd encourage you to just dive in and worry about those things later.

That being said, I would set up git. Not enough can be said on the value of using version control.