Does anyone have advise how to get started with inventing?

General advise would be great, but specifically, I am interested in learning a bit about patents. How to get one without being cheated. How to protect it once I have it. What can and what can't be patented? How do I know if it has already been done?

What is the best way to make money off of a patent? Start a business? Sell it and make something new? Partner up with a business savvy guy?

Are there any good books on this or related subjects?