Other folks may have better ideas, or they may know how to go about doing
exactly what you want - and I'm not trying to be a downer, but I doubt that the pool of "talented writers who have no clue what to write about and therefore need you for inspiration" is very large at all... If someone is talented enough to develop your ideas (and pretty much wind up doing all the detailed creative work in the process) they're going to want by far the majority of the compensation/profit. And your idea would pretty much have to be "OMGWTFBBQ!" level to attract much interest.
Collaboration is a possibility - but in addition to you having to put in a *lot* of work/time just to figure out - and describe in enough detail - the basics of characters, story arc, important events yadda yadda, you'd have to find someone who you could stand to work with (and they would have to be able to stand working with you!) who gets your vision...
Look in your local area for writers groups/clubs. If there is one the local library will probably have a way to contact them. Check you local community college, especially the adult & continuing education classes - my local CC has evening classes for writers and the odd writers workshops. I would think that these might make good hunting grounds for a collaborator. May even be a Craigslist entry or two - don't know but there's everything else...
Short of you signing a contract and paying them outright for their work, I'm not sure that you can *really* protect yourself per se - Great ideas are pretty much a dime a dozen. The *work* is in the development, refinement, and "bringing forth" the characters / storyline. You could sort of go the route of copyright, but it doesn't really protect undeveloped - undocumented - parts of your ideas, just what is written and can be considered unique traits of the existing work. You'd definitely have to consult with a good attorney for advice on how to proceed here.
Don't let me discourage you - just be aware that there's a hell of a lot more involved than having a great idea.