To start a new program in .NET

System.Diagnostics.Process.Start("http://www.ed.ac.uk");

System.Diagnostics.Process.Start("notepad.exe");

If you want to get information from a form, which submitted data using GET, just use Request.Params["id"]

string connString = "server=localhost;database=Frank;uid='sa';pwd='novell'";
SqlConnection conn = new SqlConnection(connString);

conn.Open();

string sql = "select * from addressbook where id=";

string id = Request.Params["id"];