can anyone provide/refer a proper OO type helper class for managing a singleton of the SessionFactory and then also for managing Sessions?
I've had great success in the past using Spring.NET's NHibernate support modules. See http://www.springframework.net/downloads/Spring.Data.NHibernate/. You should be able to use the OpenSessionInView module and extend your DAOs off of the NHibernateSupport DAO to get full management support of the open session in view pattern.
Additionally, although I've never tried it, you should be able to use the above stated framework even if you opt out of the reset of Spring.NET's offerings (namely IoC and AOP).