Hi,
What you are asking is a kind of project. It can be expanded to very big project but let me give you some point that you should learn.
1) Creating
StoredProcedure and use it in your application.
2) Learn about
File Handling in .NET Framework
3) Learn
N-Tier/3-Tier Architecture (How you can separate your Business/Database logic.)
4) You can also use
SQLHelper[
^] class to interact with Database.
5) And ofcourse
C# Concepts (Refer :
C# Nutshell[
^])
Best of luck
Thanks
-Amit Gajjar