As stated above, is there a legal protocol one can follow, or some type of confidentiality agreement, to prevent programmers, web developers from disclosing or using the ideas you hire them to produce ?
You could have a lawyer draft a Non-Disclosure Agreement which they would have to sign. This is fairly common practice. As for preventing them from using your ideas and making a similar site themselves, I don't really see you being able to stop that. Non compete seems reasonable in most businesses, but when you look at the business of web developing, it bomes a bit iffy. The truth is, as unique as you think your idea is, it probably isn't... Web developers get clients with ideas all the time, a lot of them are the same. So it wouldn't make financial sense for a developer to sign a non-compete when next week he may have 2 clients who come to him asking for the same thing. Now he legally can't perform his job... Ideas really aren't protected intellectual property, unless you get that idea patented.
confidnetality agreements are likely your best bet. If you bid on projects through Rent A Coder for example u can make coders fill in a Non disclosure form before work starts.