Starting at the beginning of 2009, a series of blog posts by Casey Charlton
Blogged The Ubiquitous Language
Blogged Entities and Value Objects
Blogged Bounded Contexts
Blogged There Is No Database
Blogged Command Query Separation as an Architectural Concept
Blogged Aggregates and Aggregate Roots
Blogged Services
Blogged The Repository Pattern
Blogged Living in the Enterprise
Blogged The Specification Pattern
Blogged Validity, Consistency and Immuntability