user interface help

Well, I''ve begun to embark on the task of developing a user interface for our companies game. Here''s my problem. I have no idea where to start. I''ve got a pretty good knowledge of C# and a basic knowledge of DirectX. What I''m looking for is a basic design manaul. Right. Thats it. And while I''m wishing, I''d also like a pony.... But really now, I''ve decided on a radial interface like Neverwinter Nights. It will best suit our game. And I also have a graphic artist helping me with the design of stuff. Other than that, I''m new to this. So be nice, please. b