Today Sept 3, 2012 I have delivered MSDN Webcast on Windows Phone Application Development. Thanks for the amazing responses. It went for 2 hours and so many questions
Below are some resources
Windows Phone Developer Center
This is where you go register for marketplace, submit, and manage your app publication process for Windows Phone. We also attempt to create a rational mapping of the content landscape, but we have some limitations on what we can do here, and it often ends up not being as clear as we'd like. This means that App Hub ends up 'mostly' being targeted at the actual 'program' associated with registering and submitting your application.
Learn to Build Windows Phone Apps
This is where you get the latest developer tools for Windows Phone, (always free as in beer).
Explains how you register for an account.
Explains how you submit an application for certification.
Primary Windows Phone node in the MSDN Library
This is our 'official' documentation. Note, not _all_ of the official documentation lives under this node. Since Windows Phone's application platform is predominantly based on Silverlight and XNA, you also need to be aware of the key nodes for those specific technologies as well. (supra.).
MSDN Library, primary node for XNA Game Studio 4.0
This includes developing Windows Phone games using the XNA Framework, in depth.
MSDN Library, primary node for Silverlight for Windows Phone, (WP7.1)
This is the Silverlight specific documentation for Windows Phone 'Mango'.
Windows Phone User Experience Guidelines
This is pretty comprehensive, but a little to meaty for most folks. We'll have a lot more information about UX on Windows Phone in the coming weeks and months.
Building a Windows Phone Application from Start to Finish
This is a pretty cool guide the P&P guys did, to walk you through the entire process of building an app.
Microsoft Patterns & Practices: WP Developer Guide
A set of three specific guides to building WP apps, from soup to nuts.
"How To" Index
An index of all of the 'how to' documentation put together by the doc team.
Windows Phone Training Kit 7.1
A different set of hands on labs, targeting the new features and functionality of Windows Phone 'Mango'.
Official Sample Code
This is a large set of sample code that's published inside our 'official' documentation on the MSDN Library.
Patterns & Practices Labs
Hands on Labs to go with the PNP Guide.
WP for Absolute Beginners
Astonishingly good series of many videos about how to program for Windows Phone. Even though it is targeted at people who do not know programming at all, I highly recommend it, because it is so well 'grounded,' and gives you a great understanding of why things are done the way they are in C#, IMO.
Mango Jumpstart Training
Rob and Andy deliver the end-to-end textbook on Windows Phone development, all right on your computer in an easy to consume video format. From their mouths to your brain.
Microsoft Design Toolbox training
Includes a lot on Windows Phone, including the 'extra credit course,' four projects with six sessions each, and many new 'tutorials'.
Inside Windows Phone Show
A weekly interview with a person of note involved in developing and/or evangelizing the Windows Phone developer ecosystem. Hosted by yours truly.
Streaming videos of our sessions at the MIX 11 event last April, (where we unveiled the WP Mango app platform).
Windows Phone at last November's //BUILD event.
Windows Phone at Tech Ed Europe 2012
Silverlight Toolkit for Windows Phone
This would have been ideally packaged directly within the WP SDK, but the harsh realities of a big software company sometimes mean you don't get 'ideal'. They are super important and cool.
Who can argue with 'fun'? I know i can't.
Windows Azure Toolkit for Windows Phone
Makes it easy to build apps (and games), that leverage Azure services. This is an amazing feat in and of itself, worthy of several academy awards, at least.