The EASIEST thing is to load the Footnotes plugin. Search for it at
Then load it using the standard plugin method. From your project
script/plugin install http://macromates.com/svn/Bundles/trunk/Bundles/Rails.tmbundle/Support/plugins/footnotes
Footnotes gives you extra goodness if you're using TextMate -- which
you should anyway if you're trying to learn or develop in RoR on a
Mac. I'm PRETTY sure it works without TextMate.
What it does is automatically place ruby-debug like information on the
bottom of each rendered page. Here's what it looks like on my machine:
Show: Session | Cookies | Params | Log | General Debug
Click on the link to show whatever and there you are! (The first line,
Edit: won't work without TextMate.) All this automatically turns off
when you move to Production mode.