Textt

Ubuntu
http://articles.slicehost.com/2010/4/30/ubuntu-lucid-setup-part-1
http://articles.slicehost.com/2010/4/30/ubuntu-lucid-setup-part-2

Ruby 
http://articles.slicehost.com/2009/1/6/ubuntu-intrepid-ruby-on-rails

RVM
http://d.hatena.ne.jp/hrsth/20100609/1276047000

MySQL
http://articles.slicehost.com/2008/7/8/ubuntu-hardy-installing-mysql-with-rails-and-php-options

gem
passenger
http://redmine.jp/tech_note/apache-passenger/

nokogiri
sudo apt-get install libxml2-dev libxslt1-dev
sudo apt-get install ruby1.8-dev

sudo gem install nokogiri