I didn't know where to start, so I am beginning with what I know. Many times you will see a duality, or triplicity, in Deities. In this case it is a duplicity, and also sorts itself as a physical place all of which I will cover.
There aren't many actual rites/rituals/or spells to be found on The God of Hell. Many that you will find are new, created by someone recently (though for credit, any rite/ritual/spell you find on any God/Goddess has been "created" at some point), and there is little information I have found on how he was worshipped in early Roman/Greek times.