I promised everyone that I would provide a list of resources that we brought up in class. If you think of any more that I missed, feel free to leave it in a comment and I'll merge it into this list.
Keep me posted on the progress of your apps!
Metro Tile Sources
The Noun Project - this is a great collection of icons that represent things... you know... nouns
Icon Finder - find icons on the web and get either the PNG or the ICO file
Icons8.com - a cache of free glyphs that work well with Windows 8 Metro style tiles and art
The XAML Project - more
SyncFusion Metro Studio - more
http://raphaeljs.com/icons/ - more
Visual Studio Add-Ins
Debugger Canvas - use this to visualize your code and your call stack while you're debugging. It even supports visualization of multi-threaded stacks and recursive functions.
Bug Aid - some more great help visualizing C# entities while you're debugging
ReSharper 7 EAP - perhaps the biggest source of developer joy you can ask for
Inkscape.com - this is an awesome vector based graphics tool. If you're still using a bitmap based image editing tool for generating app art, you should stop in your tracks and learn to use vector.
Kuler - a color palette picker.
ColourLovers.com - again
colorschemedesigner.com - again
None of these support Windows 8 yet of course, but they were mentioned in class so I thought I should include them...