Lesser Magic: We can start at the beginning. In English grammar convention, only the first letter of a sentence and proper nouns are capitalized; not every word (except in titles of books or other works), and not all nouns (as you would in German). If this is an error because English is not your first language, do not take offense, but rather, understand that learning this will make you more readable.
Lesser Magic can be understood in great depth from The Satanic Witch
by Anton Szandor LaVey.
Greater Magic: I suggest reviewing the final two books of The Satanic Bible
, many times if necessary. When you think you have a handle on that, pick up The Satanic Rituals
, also by LaVey. However, I expect that understanding Greater Magic will come first and foremost from The Satanic Bible[i/].
If there is any confusion about the fact that we don't believe in Satan, yet call upon him in ritual, let me remind you of the suspension of disbelief for ritual purposes. That is, doing things because it is emotionally significant, which in normal conditions you would find unlikely (like summoning devils). It should be painfully obvious, but we do not expect Satan himself to appear during ritual.