OK. So you're impatient to get started. In order to avoid damaging your new board, just read this really short list of common pitfalls.
Power the IOIO either from 5V-15V input on the VIN line or from 5V directly on the 5V line. Avoid accidental contact between the power lines and other pins / conductors. You can read more about power supply here
Not all of the IOIO pins are 5V tolerant. Some of them can only tolerate up to 3.3V. You should input 5V to the IOIO only on those pins marked with a circle on the back side of the board. If you need 5V output, also choose one of those pins, connect a pull-up resistor (10K-47K) from the pin to the 5V line, and use it in open-drain mode. You can read more about pin functions here, and more about 5V I/O here
Don't forget to turn on USB debugging (Menu > Settings > Applications > Development > USB debugging)