Database conn

Use config file to store a connection string.  There is a tag;

<configuration>
<connectionStrings>
 where you can write connection string.

And you can access it in your application using configuration like;

System.Configuration.ConfigurationManager.ConnectionStrings.Item("DatabaseConnection").ConnectionString

And to inseert update and delete from db go thr these links;

http://www.codeproject.com/KB/database/simpledbreadwrite.aspx

http://www.java2s.com/Code/CSharp/Database-ADO.net/IllustrateshowtoperformINSERTUPDATEandDELETEstatementsusingADONET.htm

Best Luck!!!!!!!!!!

Sujit.