If you've a developer account, go to http://dev.windowsphone.com. If you don't have a developer account, you can register one here:
https://dev.windowsphone.com/en-us/join
On this page, click on the dashboard. On Dashboard, you'll find a link to 'SUBMIT APP' (direct link
here).
Let us know if you need more help with this.
Mayur Tendulkar | Microsoft MVP - Windows Phone Development | http://blog.mayurtendulkar.com
