To be an incubator company you have to have some experience taking concepts all the way to market. What you have an 'an idea' which is only valuable if you can somehow develop it.
Why not just shop the idea around and see if anyone wants to develop it for you and you can own some of the business? Unless you have something specific to offer beyond the original idea, that is really all you will be able to get.
Sure, use an NDA form if you feel that you need the protection. Don't be surprised if some of the more experienced investors won't sign it, though If your idea is FANTASTIC you should have no problem getting someone to partner on it. I am always looking for deals like that myself (i.e. equity partnerships) and it's done all the time.
Unless you know how to write a business plan (a REAL one) don't bother. Just write a one page max brief on what the product is and how it will make money. Then send it to a few people and see what response you get.