inserting data into SQL Server from vb.net

The best approach would be to use a parametrized query to avoid SQL injection attacks:

Public Sub Processsales()
    Dim cust_guid As Guid = Session("guid")
    Dim Iden As Guid = System.Guid.NewGuid()

    ' define your SQL query and use parameters for the values to be inserted           
    Dim sqlQuery As String = "INSERT INTO WebSite.wTranH([WebTranHGUID], [TranType], [LOCTN]) VALUES (@HGuid, @TranType, @LocTn)"

    Dim connString As String = ConfigurationSettings.AppSettings("SqlConnectionString")

    Using connection As New SqlConnection(connString)
        Using command As New SqlCommand(sqlQuery, connection)
            connection.Open()

            ' add paramters and their values to the SqlCommand instance
            command.Parameters.AddWithValue("@HGuid", Iden)
            command.Parameters.AddWithValue("@TranType", 2)
            command.Parameters.AddWithValue("@LocTn", 5)

            command.ExecuteNonQuery()
            connection.Close()
        End Using
    End Using
End Sub

You should use:

values ('Iden',2 ,5 ) 

instead.

You have two errors in your sql string.
You pass fixed values for TranType and LOCTN columns, but the WebTranHGUID column should get the value of the structure Iden not its name. Of course the values should be passed without brackets to not confuse with column names.
You should change your code to concatenate the value of Iden to the sql command in this way:

Public Sub Processsales()

    Dim cust_guid As Guid = Session("guid")
    Dim Iden As Guid = System.Guid.NewGuid
    Dim ssql As String
    ssql = "Insert into WebSite.wTranH ([WebTranHGUID],[TranType],[LOCTN]) " + 
    "values (" + Iden.ToString + ",2,5)"

    Using connection As New SqlConnection(....))
        Dim command As New SqlCommand(ssql, connection)
        connection.Open()
        command.ExecuteNonQuery()
    End Using




End Sub