In particular, banks do not lend out deposits, at least not in any meaningful way, and the so-called money multiplier is non-existent.
To get up to speed on such things, I would recommend the blogs of economics professor Bill Mitchell. His style is a bit rambling without much polish, since he writes one entry every day, but I found it very worthwhile for getting a deeper understanding. Consider looking for entries with "money multiplier" in the title in the index here: http://bilbo.economicoutlook.net/blog/?page_id=1667
What most people don't realize is that banks don't have to actually have the money they lend out. That's the basis for our monetary system and while it has nice qualities, like spurring innovation, there are some undeniable drawbacks.