The original Necronomicon is a tale made up by the author H.P. Lovecraft in his horror series about Cthulu. The whole concept of the Mad Arab and his book is fictional.
Since then there have been a number of different books published called the Necronomicon, perhaps best know is the Simon Necronomicon. The books are full of supposedly ancient spells and rituals, but in fact most of the material in them is simply a mishmash of other fantasy and factual material.
I think it might be possible for someone who knows what they are doing to work with the Necronomicon to a certain extent. But it is by no means this dark and mysterious book that summons evil beings and drives men mad. It is entirely a work of fiction.