Rails Magazine is a well designed magazine dedicated to "fine articles on Ruby & Rails" and the recently released issue #6 is special in being nearly entirely Ruby focused. Topics covered include Haml, Sass, Capistrano, Hpricot, RubyConf India and RVM, as well as interviews with Sarah Allen and Michael Day (of PrinceXML).

The PDF version of Rails Magazine is free, but you can buy a print edition through MagCloud for less than $10.