http://www.developforwindows.com/

Some cool sample applications can be found on this site that will most certainly help a lot with getting started. Also tookits are downloadable from this page!

Fishbowl

Do you want to access, manage and interact with your Facebook account quickly and directly from your desktop? Fishbowl is a cool Windows Client WPF app that does exactly that by providing a richer and more powerful experience.

Fishbowl
FlashCard

Have you ever needed to memorize words in a new language, or names of certain people or objects? If so, now you can use FlashCards.Show to easily produce decks of flashcards — making learning easier and fun!

FlashCard

 

Enjoy!

 

Hans