Is this a good guide if I want to implement the repository pattern in my asp.net mvc application?
Mostly. I haven't read it fully, but I prefer S#arp Architecture idea of SaveOrUpdate (mapped from NHibernate) for entities, it's more convenient thant Add/Remove. But it may be just personal preference. In any case you can look at S#arp for already implemented repositories over NHibernate/FluentNHiberate.