It's pretty simple though,
SqlConnection con = new SqlConnection("DatabaseConnectionString");
SqlCommand cmd = new SqlCommand("SELECT SomeColumn FROM SomeTable", con);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);
foreach(DataRow dr in dt.Rows)
{
ComboBox1.Items.Add(dr[0].ToString());
}
-KR