Cut 2 female header strips of 15 pins each.Place the nano board for reference.Insert the two headers according to the nano pin.Check it whether the nano board is perfect to fit into it.Then solder it back side.
Insert two rows of male header on both sides of nano borad for external connections.Then join the solder points between arduino pin and header pins.See the above picture.
Initially I forgot to add Vcc and GND headers.At this stage you can put headers with 4 to 5 pins for Vcc and GND.
As you can see I connected the voltage regulator 5V and GND to the nano 5V and GND by red and black wire.Later I removed it and soldered at the back side for better look of the board.