For reference, here are a collection of links to Windows Phone 8 development documentation and training materials.
Absolute Beginners: http://wpdev.ms/beginvids
Jump Start: http://aka.ms/wp8js
Design boot camp: http://aka.ms/wp8designbootcamp
Training Kit: http://aka.ms/wp8hol
Are you a Windows Phone developer? If so, you could be getting rewards for the apps you build and the success they achieve by joining Nokia's DVLUP program.