Building a Windows Phone 7 app from start to finish

Newly published in the MSDN library, this documentation and accompanying sample application will get you started building a complete application that targets Windows Phone OS 7.0. You will learn about common developer issues in the context of a simple fuel-tracking application for your car named Fuel Tracker. This topic describes things you should know before you start creating your Windows Phone application and includes a list of other useful resources to help you out.
Among the topics:

• Defining your application from an idea
• Creating a new Windows Phone project
• Creating pages
• Navigating between pages
• Laying out a page
• Using controls to create the UI
• Adding images and icons
• Creating a consistent look
• Displaying data
• Creating data classes
• Saving and loading data
• Restoring your application after deactivation
• Validating data entry input
• Incorporating photos on Windows Phone
• Publishing your application in the Windows Phone Marketplace

Get started here.