Hi,
You need to learn about SQL query, ADO.NET, and C#.
Do not start with solution oriented learning, start reading some books , articles and try to create small examples from articles.
Download opensource code and analyze the code. It's not about one day journey, you need to learn language and then you are ready to answer your question.
Helpful material:
C# Nutshell ebook[
^]
MSDN ADO.NET[
^]
MSDN Windows Forms[
^]
And any book from APress publication(good for beginner)
hope this information helps you,
Thanks.