What is the most powerful tome you have ever WORKED with and not just read. The idea is to give new magicians a good chance on the right path they seek and skip all false books that will only work doubt into their heads
New Avatar Power by Geoff Gray-Cobb,
Babylonian Sacred Words of Power, Carl Nagel
Lessons in instant ESP, David St. Claire
Damn I thought we were talking about alcohol…
Hands On Chaos Magic and the Sorcerer’s Secrets would be my go to then 
Well, it’s not a book per se, but it is part of EA’s newsletters: [url=http://www.becomealivinggod.com/newsletter/4-incantations-to-conjure-limitless-power.php]http://www.becomealivinggod.com/newsletter/4-incantations-to-conjure-limitless-power.php[/url]
That last chant is the most deadly thing i have come across, and it is my main practice. Great for summoning demons if chanted for about 10-15 minutes.
Just fitting that chant into a ritual can work wonders. If one starts with initial meditation,then goes to sigil opening, and then chanting that chant, then there is a full ritual already.
And beginners should know that no physical manifestation of the spirit is necessary with that chant especially. Just use it and give the spirit a task.
easy but very powerful.