Updating DB with Values on Windows Screen?

Question

  I am new to this have been thrown into the Lions den with only a class and a book.  So I need a little help with how to update the DB from the fields that are entered on the screen.  I actually provide the value with the code nad it works :
cmd.CommandText =
"UPDATE BM_DISPUTES SET DIS_LASTNAME = 'DOE', DIS_FIRSTNAME = 'JOHN'" +
"WHERE DIS_NO = 17";
So if someone could help me out with a simple example so I can get started I certainly would appreciate it. I will need for Update, Add and Delete...
Thanks,
Ben
PS; I use VS2010 C# and this is a Windows application...