Both are areas I've dabbled in, but this year I want to improve on them. So I'm starting with WPF and have published WPF Tutorial one, an introduction to WPF.
I've actually done some WPF at work but it's 95% C# and 5% XAML, which is not really the way it's supposed to be done! Expect more in the next few weeks.
- Tutorial link added to C# Tutorials page