Welcome to the Android OS world, and I hope you are enjoying your Atrix.
I am guessing you are concerned about data consumption by your device.
All apps which obtain data from the network, such as Google Maps, consume data. But, Google Maps does not use data, unless you actively use the app. So, if Google Maps is open and you are just letting it sit there, no data is consumed. Once you start messing with it, then it starts eating data.
You can observe this process, easily. There are up and down arrows at the top of your screen. Anytime you have an app open, and you are seeing those up and down arrows lit up, you are using data.
Some functions of your Atrix use data, by themselves. For example, if you have a weather widget going, it will refresh its weather info, from time to time, and that will eat data. Your Gmail or other email apps will check for mail, from time to time, and that will eat data, silently.
So, there's some processes which use data silently, while others depend upon your actively using it. The key to knowing when the data is moving, or not, is to watch for those up and down arrows at the top of your screen. When they are active, so is the data!
I recommend checking the "My AT&T" app, which is built into your Atrix. It will track your data usage, during each month, and tell you how much data you have left, before you reach the limits of your plan.
Finally, there is a power setting which you can use, which automatically shuts off data use, if the Atrix is left idle for 15 minutes.