A couple of thoughts you might consider:
A strain gauge output is very very low. Typically an instrument amplifier is needed before going into the Arduino A/D.
The strain gauge signal is usually so low that ambient noise becomes an issue. Look in ebay for a HX711 based strain gauge measurement board. Better than the instrument amplifier mentioned in the previous statement.
Bonding of a strain gauge is critical. Look at Omega engineering for some guidance.
Strain gauges change resistance with temperature. Need a plan to deal with this.
Google Strain Gauge tutorial for additional information. I found several with a simple "strain gauge tutorial" search.
Good luck.