Some more links for knowing about XAML -
How XAML works :
http://www.i-programmer.info/programming/wpf-workings/446-how-xaml-works.html
The New Iteration(A must read
whitepaper):
http://windowsclient.net/wpf/white-papers/thenewiteration.aspx
It is also good to have knowledge of BAML(Compiled version of XAML)
B is for... BAML:
http://blogs.msdn.com/b/jimoneil/archive/2009/01/12/b-is-for-baml.aspx
Compiled XAML = BAML not IL
It may be a little high level but you must know the basic guidelines/conventions (in case you work on a commercial project later):
XAML Guidelines :
http://www.cookingwithxaml.com/content/xamlguidelines/xamlGuidelinesDraft0.pdf
XAML Conventions:
http://groups.google.com/group/wpf-disciples/web/wpf-and-xaml-coding-guidelines
XAML guidelines and best practices:
http://www.85turns.com/2009/02/09/xaml-guidelines-and-best-practices/comment-page-1/#comment-1419