It's good to see posts about Fluent NHibernate popping up. The NHibernate FAQ blog is running a good series of articles showing various mapping techniques and usage scenarios....

• Part 1 - Intro to Fluent NHIbernate
• Part 2 - Mapping Value Objects with Fluent NHibernate
• Part 3 - Mapping Associations with Fluent NHIbernate