I have done this before in previous posts but I wanted to have an easy way to point developers to great resources when you are building Windows Phone or Windows 8 applications. If you ever want to get back to this page you can just go to http://bit.ly/wpw8resources (Standing for Windows Phone Windows 8 Resources). I will add to this page often and keep building on it. In addition, I will have one set or resources going forward and will only notate when it is specific to either.
Icons
Modern UI Icons (FREE) http://modernuiicons.com/
Design Help
MetroGridHelper. A visual guide overlaid on your application – http://www.jeff.wilcox.name/2011/10/metrogridhelper/
MetroGrid Component for Windows Phone (Based on code above) http://www.windowsphonegeek.com/articles/MetroGrid-component-for-Windows-Phone
Advertising
Advertising sizes available for Windows 8 using Microsoft Advertising http://msdn.microsoft.com/en-US/library/hh506361(v=msads.10).aspx
Transferring Phones
Free Contacts Transfer application for Nokia phones