The ritual for summoning Shub-Niggurath.
The ritual for summoning Azathoth.
The ritual for summoning Hastur.
The Necronomicon from AbyssalCraft has the information about how you set up and perform rituals, along with pages for each of the rituals included in By The Gods.
The ritual for summoning Yog-Sothoth
The ritual for summoning Dagon.
The ritual for summoning Nyarlathotep.
The ritual for summoning Cthulhu.