Andy Wigley recently delivered the JumpStart video series and these are now available on Channel 9.  There is a full course so you’ll need a bit of time to run through all of these but they are a great place to start if you looking to start writing apps for Windows Phone. 

Full course outline:

At the Microsoft Virtual Academy:

If you prefer a different way of learning, you can take the Building Apps for Windows Phone 8 Jump Start course at the Microsoft Virtual Academy which includes the same video content, but allows you to track your learning through your dashboard at the MVA, and accumulate points as you take part in the learning. There are also many other courses and Jump Starts you can take part in.

I’ve done my phone app… Now I want to port it to Windows 8

No problem at all. If you’re looking to move your phone app to the desktop there are some great resources here: