User Interface Standards and Guidelines

Question

Hello,
 I have recently joined my company's Database and Coding Standardization Committee which will be responsible for creating and enforcing all Application Development standards for our future migration into .NET.
 I am primarily responsible for standardizing User Interfaces and was wondering if anyone knew where I can find Microsoft's guidelines for creating UI? I know naming conventions, but I am more interested in Object Standards (ie: button sizing, colors, when to use combo boxes, etc).

 Any assistance would be greatly appreciated