How do I get the Itead 3G shield to work?
What should I be seeing if anything?


Usually, a GSM module will not send (unsollicited) messages. Everything it sends will be an response to an received message.

Try sending AT (with a new line/carriage return (depending on the GSM module)) to the GSM module, it will send something like AT OK or just OK

And you didn't set the pin directions (output/input), might be doen by the serial libraries, but beter be safe if you're not sure.

Also check your wiring (jumpers on UART multiplexer in this case?) and share it with us, Rx/Tx wiring often gets messed up :)
If your GSM module has a USB connection, you might even test it with a terminal (taking out the Arduino in the middle, thus any wiring/code between.)

I also suggest you change the name of the serial connection to the GSM to something like gsmSerial rather than mySerial (which could be anything).

Be sure the 3G shield has enough power (amperes), otherwise they might reset when attempting to make an connection.
(Put the external supply in the Arduino, rather than USB powered)