Outside of the source code, is there any extensive documentation on the Magento ORM? I get the basics, and can usually dig through the Mage code base, litter it with Mage::Log
Since this question was answered, some documentation has been created on the ORM at the magento knowledge base.
Introductory information: http://www.magentocommerce.com/knowledge-base/entry/magento-for-dev-part-5-magento-models-and-orm-basics
Advanced ORM usage and the EAV system: http://www.magentocommerce.com/knowledge-base/entry/magento-for-dev-part-7-advanced-orm-entity-attribute-value
Working with the Varien collections (lazy loading, filtering, etc...): http://www.magentocommerce.com/knowledge-base/entry/magento-for-dev-part-8-varien-data-collections