Generally when you hire people to work for your company, you want it to be a work-for-hire agreement. That means they can quit anytime they want and you can fire them at any time that you want. Within that agreement it should have confidentiality provisions as well as provisions that say that all the work that they do for you belongs to the company. Those are really important pieces to the puzzle that can throw a hook into your business plan if they are not there, especially when you are working with important people and when you are working with technology companies.