Help me Hire C#, ASP.NET MVC Developers

I need to hire someone to help me hire developers via oDesk, Guru, or Freelancer. As such you need to know how to evaluate the quality of developers. I am looking for developers that can code fast, accurately and efficiently. In order for you to be able to evaluate developers you yourself need to be a developer with these skills. Perhaps you want to give them a test, it's up to you. Skills needed for my projects include ASP.NET MVC 4.0, Twitter Bootstrap, HTML5, CSS3, MS SQL, Java Scripting, Photoshop (not required, but useful), PSD-to-HTML (I may provide PSDs and you will need to be able to implement based on these). One of the key things when hiring people is their availability on Skype and someone that provides frequent updates on a staging server (I can provide my own server access). The person needs to show result on a server on an on going basis. Please tell me how you would go about evaluating the quality of the developer. Also, how to handle the case when a developer cannot perform the tasks. We need to agree on a fee or scheme you would earn for providing a developer. Suggestions are welcome.