How does one assign column names to tables in dataset?

How does one assign column names to tables in dataset?

I have this code
SqlConnection conn = Database.GetConnection();
//not sure why doing this bit (bit between this comment and next
//SqlDataAdapter adapter = new SqlDataAdapter("Select * From
CarType", conn);
DataSet DataSetRentals2 = new DataSet("CustomerSQLTable");
DataTable table = new DataTable("CustomerSQLTable"); //you can
name it
DataTable table2 = new DataTable("CarRental");
using (SqlDataAdapter adapter = new SqlDataAdapter())
{
adapter.SelectCommand = new SqlCommand("SELECT * FROM
Customer", conn);
conn.Open();
///this might brake the code
///
adapter.Fill(DataSetRentals2,"CustomerSQLTable");
adapter.SelectCommand = new SqlCommand("SELECT * FROM
CarRental", conn);
adapter.Fill(DataSetRentals2, "CarRental");
adapter.Fill(DataSetRentals2, "CarRental");
}
CustomerGrid.DataSource = DataSetRentals2;
CustomerGrid.DataMember = "CustomerSQLTable";
CarRGrid.DataSource = DataSetRentals2.Tables["CarRental"];
CarRGrid.DataMember = "CarRental";
the teacher gave me this code to link them in a relationship so that when
i click on one customer number in one data grid and for it to only return
corresponding records in the other.
DataRowView selectedRow =
(DataRowView)CustomerGrid.SelectedRows[0].DataBoundItem;
DataSetRentals2.Tables["CarRental"].DefaultView.RowFilter =
"CustomerNo = " + selectedRow.Row["CustomerNo"].ToString();.
so what i think i need to do is to name the columns in the dataset. But i
have no idea how to do this. I'm sure there must be a way an I'm sure you
guy's can easily tell me it. Thank you in advanced.