Everything about the illuminati explained!

I have heard an immense amount of info about the illuminati, some logical, some completely illogical, and I want to know more....

What different levels of power are involved?
Who makes up the few "leaders of the elites"?
Are they behind most of the corruption and propaganda?
Are children involved and exploited at a young age?
Are they in communication with other beings in the universe?
Is the saying "selling your soul" a correct way to explain this?
From all of where do they operate from?
What different agencies are involved and what is their purpose?