Question about which tools to use, bugs, the best way to implement a function, etc should go here. Don't forget to see if your question is answered in the wiki first! When in doubt post here.
Well, if it's a new OS then you have to write (or port) applications for it. (Or find someone to do this for you.)
Unless, that is, you have coded your OS to be 100% compatible with an existing OS, so that you can use existing applications. If that is the case I would advise you to get a good lawyer before you attempt to release it for commercial use, both to protect your intellectual property and to make absolutely sure that you are not infringing one someone else's IP. In any case that's probably a good idea before asking for money for your OS.
Why the screenshots of the Windows 8 license pages?