What you are looking for is Active Directory delegation. MSFT has a published best practice document that you can use http://www.microsoft.com/en-us/download/details.aspx?displaylang=en&id=21678.

  However its very simple to implement: http://www.windowsecurity.com/articles/Implementing-Active-Directory-Delegation-Administration.html

  I also have a simple step-by-step setup of delegation for an open source AD application I wrote that you can take a look at: http://umanage.codeplex.com/wikipage?title=Active%20Directory%20Configuration

What you are looking for is Active Directory delegation. MSFT has a published best practice document that you can use. However its very simple to implement. I also have a simple step-by-step setup of delegation for an open source AD application I wrote that you can take a look at: