You should probably start to explore the KinectFusionExplorer-WPF KinectFusion available on codeplex:
http://kinectforwindows.codeplex.com/SourceControl/latest#v1.x/ToolkitSamples1.8.0
KinectFusionExplorer-WPF has some nice utility methods for matrix transformations, (virtual) camera configuration, etc.
The process for doing the AR augmentation is:
- viewport: set your viewport using the same resolution as the one for the camera image,
- video background: retrieve the video image from the Kinect and displays it in the background (either as done in the SDK examples or using a textured quad with the video image as done more traditionally),
- geometric registration: use WPF3D and set a Camera object using: the intrinsic parameters of the Kinect camera (or the same ones used by KF), the camera pose you get via GetCurrentWorldToVolumeTransform() from your volume,
- rendering: set any local transformation you want for your model (xaml) and render (using the way it's generally done with WPF3D).