drewdavis:
As you know I'm new to the Arduino (and electrical stuff) and I do not understand the data sheet completely.
- When it says the "typical voltage loss" does that mean that I can rely on the fact that it will typically be that much lower or are their test results not practical when it come to real applications?
It means exactly what it says. The voltage drop will typically be somewhere near the "typical" figure, but it could be as high as the maximum figure.
drewdavis:
2. What exactly is voltage loss. I know that it means you lose voltage, but when do you lose it? Do you lose it when power goes into the shield, and can combat that with a bigger battery, or can you combat voltage loss with a good program?
It is the difference between the voltage supplied to the H-bridge and the voltage appearing across the motor when the H-bridge is on. You can combat it by increasing the voltage going in to the H-bridge. The lost power is dissipated as heat.