The Necronomicon was originally a nonexistent fictional text that was referred to in H.P. Lovecraft's stories. Since then, a number of different "Necronomicons" have appeared. I am not aware of any good reason to believe that any of these are the "real" Necronomicon originally referred to by Lovecraft.
Personally I have no use for any of the Necronomicons.
Some people find passages from one or more of the Necronomicons to be useful in ritual. I have no problem with this as long as people don't claim it's genuinely ancient.
The Necronomicons will not be part of Church of Azazel ritual.