Resources: List of Code Generation Tools, List of O/R Mappers
Oren Eini gave an NHibernate Workshop on advanced NHibernate. Someone taped the presentation, but I am not sure if the video/audio is good enough to really grasp the material. Actually, I think the audio is pretty good, but I can't really see any of the code being demonstrated.
Still, if you are looking for some advanced NHibernate Material, you can check out the video here.
Personally, I think now is a good time to move away from Microsoft O/R Mappers and move to a third-party solution. The death of LINQ To SQL gives me little confidence in what Microsoft is doing associated with data access.
You can find numerous data access solutions for 3rd parties that continue to get better and better over the years and are not thrown away. O/R Mappers that come to mind ( in no particular order ) are:
They all support LINQ, with the exception of NHibernate, but I know NHibernate will have a LINQ Provider soon.
NHibernate Tutorials