Storing Objects in a Database
Usenet articles on how one can make objects persistent without the code becoming dependent on a specific database technology.

Mapping Objects to Relational Databases
Explains how to map inheritance hierarchies and many-to-many relationships to a relational data model by yourself.

Using Object-Oriented Databases: A Step-By-Step Tutorial
Walk through of the development of an OODB application complete with source code. Running example is a phone book application using Java, XML and Objectstore PSE.