Do you know at least the basics of WPF? Well, if so, you probably know how to write UserControls :)
So, my advice: at least learn the basics of WPF and XAML. Return for advice if you are stuck.
And yes, you are using VS and / or Blend. (Blend is specifically for more graphically intensive / advanced controls).
There is a lot of introduction to WPF tutorials. But be prepared to wean what you know about UI design / creation. But your efforts will be generously rewarded, WPF is quite difficult to get in, but it is amazing when you hang it.