Should I be afraid of sharing my idea ?

Don't be afraid of sharing ! Share your ideas with peers and experts, you'll be surprised at the good feedback you will get. Obviously don't go crazy in sharing your idea publicly but definitely don't hold on to your idea and overprotect it, chances are you will never do anything with it if you do that. Hiring a developers to just do the work is usually NOT the best way in building a startup, instead look for a co-founder or for a smart developer who you will give a good chunk of equity to. As things evolve his input will be as much valuable as yours and maybe even more.

The other best alternative to sharing, is doing it :) Using open source and agile dev techniques you can very quickly build products (you and your co-founder/team) release them, share with the world, get feedback and track user's behaviour on the site and fix continuously in the open:)

So to resume, share with peers and experts to get early feedback (don't share with the world just yet), jump on the idea and just do it, share with the world (launch), get feedback and track usage behavior, fix in the open ...

I think that your idea will naturally change a little bit between now and time you execute and go to market with it.

I'd recommend speaking to people who you think are smart about the idea to see what they have to say.

Also, when you find smart people, make them a part of what it is you're working on. See if they could be a good fit for a cofounder. Also, you could try to make people advisors on your company's board. The possibilities are endless.

Go with a developer that would have no interest in implementing your idea. If you're in the Middle East, work with someone from Asia or US.