welcome to BuildersInventions! Do you have leagal protection for your prototype? If so you could publish it here and get feedback. You may ant to talk to derek Pater and get his impressions. He's a builder-inventor from Australia and has five tools under his belt. Feel free to ask me questions.
In that case you should keep it under your hat. Don't publicize it. If you show it to strangers have them sign a non-disclosure statement. However, it really depends upon what kind of invention it is. Derek Pater, a member, has his own method that works for him. Sometimes it's not worth getting paranoid about a patent.
I have quite a few prototypes for home,garden,work etc. I just recently got off my butt and decided to educate myself on the patent process.there is a lot of material on the gov. website to go through. Are there any websites that can help simplifythe process that are not scams.
I did my own patent for the CordSnake. I used the Nolo Press books on Provisional Patent Application and Patent Application. I had to make changes to the application after it was initially rejected by the USPTO.. But I expected that, because the books talked about that. It all depends upon how complicated your invention is. Patenting is secondary to marketing. Don't waste your money on legal fees until you've thoroughly researched the market potential for your invention.