Mike Naberezny has posted a few more articles to the "Rails for PHP Developers" website (based on this book) covering some more of the basics.

There's three new tutorials posted:

• Ruby Block Scope - the basics of Ruby block scope, a common point of confusion for PHP developers new to Ruby.
• Variable Arguments - an article that shows two common API patterns found in Rails, variable arguments and option hashes, and how to implement them both in PHP.
• Regular Expressions in Ruby - a useful reference that maps all of the common PHP regular expression functions to the equivalents in Ruby.

Check out the rest of the site for even more great content.