We use CruiseControl.NET and UppercuT (which uses NAnt) to do this. UppercuT uses conventions for building so it makes it really easy for someone to get started by answering three questions (What is the solution named? What is the path to source control? What is your company's name?) and you are building.
http://code.google.com/p/uppercut/
Some good explanations here: UppercuT
