First Rails Configuration from Lynda.com tutorial, can't launch using rails server

When i tried rails server I got:

/Library/Ruby/Gems/1.8/gems/mysql2-0.2.7/lib/mysql2/mysql2.bundle: dlopen(/Library/Ruby/Gems/1.8/gems/mysql2-0.2.7/lib/mysql2/mysql2.bundle, 9): Library not loaded: libmysqlclient.18.dylib (LoadError)
  Referenced from: /Library/Ruby/Gems/1.8/gems/mysql2-0.2.7/lib/mysql2/mysql2.bundle
  Reason: image not found - /Library/Ruby/Gems/1.8/gems/mysql2-0.2.7/lib/mysql2/mysql2.bundle
    from /Library/Ruby/Gems/1.8/gems/mysql2-0.2.7/lib/mysql2.rb:8
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.11/lib/bundler/runtime.rb:68:in `require'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.11/lib/bundler/runtime.rb:68:in `require'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.11/lib/bundler/runtime.rb:66:in `each'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.11/lib/bundler/runtime.rb:66:in `require'
    from /Libr开发者_如何学Cary/Ruby/Gems/1.8/gems/bundler-1.0.11/lib/bundler/runtime.rb:55:in `each'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.11/lib/bundler/runtime.rb:55:in `require'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.11/lib/bundler.rb:120:in `require'
    from /Users/inathan/sites/simple_cms/config/application.rb:7
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.6/lib/rails/commands.rb:28:in `require'
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.6/lib/rails/commands.rb:28
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.6/lib/rails/commands.rb:27:in `tap'
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.6/lib/rails/commands.rb:27
    from script/rails:6:in `require'
    from script/rails:6

I thought I followed the steps verbatim, but now I'm stumped. Thanks in advance...

You need to install mysql from mysql official site, make sure it is started and then install appropriate mysql gem (mysql for rails 2.x and mysql2 for rails 3.x)