Beginner Music Project

Question

Hello,
My name is Mert, I live in Turkey, I'm 15 years old and I'm new to programming. I want to do a Windows Forms project about music, I want to record the musical notes(A, B, C etc.) and I want to make a programm that plays these sounds. The notes will be played when their Buttons are pressed or when their letters are pressed. However I have no idea where to start and how to play the notes. How do I achieve this? I use Visual Studio 2008.

Edit:
I tried to start by creating Buttons and a Textbox. I created buttonclick events and showed messageboxes when the buttons were clicked. The messageboxes will be changed with the Notes when somebody tells me how to do that. I made the Textbox becuase I didn't know how to do it without a Textbox. Basically people should write the letter they want and press another button. The buttonclick event for the button should get what letter is written in the textbox. I tried to do that via "switch" but failed.

So 2 questions:

How do I get what is inside a textbox and use it in a "switch"?
How do I use Musik files in a buttonclick event?