You should generally just
Google[
^] for source codes or articles.
The following would help you out in creating a File Transfer Protocol server.
Creating an FTP Server in C# - with IPv6 Support[
^]
Secondly, read
System.Net
namespace, to learn more about networking and read about FtpWebRequest and FtpWebResponse to wrap the basic functions of the FTP server using .NET and Visual C# on
MSDN[
^].