This post describes the steps to create windows store App with C# and xaml. Before you start you need to have window 8 installed and you also need to install Microsoft Visual studio 2012 express for windows 8 which can be downloaded from here and also need developer license, you obtain the developer license from store menu
Windows Store for Developers
Windows store is really an important part of Windows 8 platform. Windows store is the place where user find the metro-style apps. Windows Store is the distribution point for metro style applications. The idea behind building the windows store is connecting people to as many apps as possible. Additional details about the Developer opportunity coming on windows 8 with the windows store can be found...