Project: design decentralised P2P system. With C# (.NET 2003), SQL server 2000 database

Hello all,

I am beginning on a Project: A decentralised system (no central server), which arranges appointments between users. It is like a Meeting Management application (resembling the look of MSN).

I am to use:
.NET C#
Microsoft SQL server 2000 (database)
IIS (not sure about server)
required to have SOAP components (therefore XML)

I have been teaching myself Visual Studio (C#), and SQL server database. I have come to the conclusion that I am not sure whether my application is considered a "Web Application" or a "Windows Application". It is not a web site I am creating, therefore I dont know if I should be reading books on ASP.NET or ADO.NET??

If each user, has their own database and a server communicating between them, how do I go about such a task without wasting too much more time.

I hope my explaination is not too brief, I am more then happy to say more on the specs. I really need some thorough steps and advice.

Thank you,
Rad.