Windowsform Applications By Using 3tier

you can get idea an idea how to insert, update , Delete record on datagrid view control in winform from here:
http://www.c-sharpcorner.com/uploadfile/kannagoud/insertupdatedelete-in-datagridview-using-linq-in-windows-forms/

and 3-tier architecture in a winform app:

http://www.dotnetfunda.com/articles/article71.aspx