You can search for US patents here.
http://www.uspto.gov/
Google is also putting together a nice patent search engine
http://www.google.com/patents It finds all my patents whereas the USPTO page seems to miss some.
There are people here at my workplace who have made $1M with a single patent. Our company gives inventors a 10% cut of royalties, and one patent for the invention of Chemical Vapor Deposition (US Pat. 4066481) made over $10M for the company. But TTE is right, patents can often end up in protracted legal battles like the one over RIM's Blackberry when big $$ are at stake. However, lots of companies will license patents without a fight if they are approached, but it takes a dedicated effort to track down and negotiate.
Before a disclosure is filed, our company, like many others, has an intellectual property committee review the idea and decide if it is worth patenting. A single patent around here can cost $10k to $20k, plus there are maintenance fees and so on, and more good ideas than money. You would be advised to get independent validation of the value of your idea. There are companies that will do this for you. If you sign a non-disclosure agreement with them you will be protected.
Also, be aware that a US patent only buys you protection in the US, so if you want protection in Europe and Asia you need to file additional disclosures and pay more money.
The bottom line, however, is that a paten has no value unless someone uses the idea. That means it should be part of a business plan to commercialize the idea, and will almost always will require significant investments beyond the patent.