This is a fairly simple breakout. The sensor itself is super tiny and in the middle of the PCB. We have all the useful pins broken out in to a 0.1" spaced header at the bottom

• VIN - this is the power in pin, give it 3-5VDC. It is reverse-polarity protected. Use the same voltage as you do for the controlling microcontroller's logic. For an Arduino, 5V is best.
  
• GND - this is the common power and data ground pin
• 3vo - This is the 3.3V output from the onboard regulator. It will be at 3.3V and you can grab up to 100mA from this to power other items
• SDA and SCL - these are the I2C data and clock pins used to send and receive data from the module to your microcontroller. There are 10K pullups on these pins to the VIN pin. You can connect these pins to 5V I2C lines, there are level shifters on board to safely bring the pins down to 3V
• RDY - this it the 'data ready' pin output. If you want to stream data at high speed (higher than 100 times a second) you may want to listen to this pin for when data is ready to be read. Check the datasheet for more details about using the RDY pin, we don't use it because we don't read that fast!