Last month I noticed the lack of a good ActiveRecord tutorial/screencast that goes from basic to advanced usage (with examples). So, I decided to put together a presentation on ActiveRecord for the Orlando Ruby Users Group.
Who invented ActiveRecord and why
How to use ActiveRecord
Basic model to table mapping
has_many relationships
Magical counter fields
Many to many relationships
has_many => through
Polymorphic relationships
acts_as_taggable