get yourself a good non-disclosure agreement and have anyone dealing with your product sign it.
what i have gathered researching a few ideas i had interest in patenting,including talking to a man who went through the whole process.
when all is said and done a patent cost about $20,000.
a patent is only a strong as the money behind it.
if a corporation wants your product they will do what they want and when you try to stop them they will drag you through court till you have nothing left to spend.
there are many people out to take advantage of would be patent filers.