I recently gave a presentation at the Central Iowa Drupal User's Group about entity reference Below are links to the slides and some resources mentioned during the presentation.
- Definition of terms https://www.drupal.org/node/1261744
- Drupal 7 Entity API https://www.drupal.org/project/entity
- Drupal 7 Entity Reference https://www.drupal.org/project/entityreference
- Entity Connect https://www.drupal.org/project/entityconnect
- Corresponding Entity References https://www.drupal.org/project/cer
- Entity Relation Diagram created with https://www.gliffy.com/