Useful Rails links for achieving something specific

A set of links to webpages describing how to achieve a specified task in Ruby on Rails, i.e. not a collection of generic Rails resources.

• Rails Plugin to Validate (X)HTML and CSS – A Rails plugin that adds test assertions for validating (X)HTML and CSS - useful for testing views.
• Quick tips about using rake to manage your database schema and fixture data – A guide to using rake for getting data into and out of your database via fixtures.
• Dump or Slurp YAML Reference Data (and Fixtures) – A Rails plugin for generating a fixture from an object.
• Rails Migrations – An introduction to Rails migrations, with example code.
• Loading Fixtures in a Migration – How to use fixtures from migration code.