When Wi-Fi isn't available, you can't get online. Well, you can't get online without a subscription to a cellular data plan with a cellular data provider, and you have to be within range of your provider's cell towers. For the Xoom, that means signing up with Verizon, which you learn how to do shortly.
For cellular data, I'm not going to detail the history of the technology or include everything you might encounter; it doesn't really matter. You'll connect to the network that's available to you, and you'll be connected to the fastest one if more than one option exists. It might be important to know how you're connected though, especially if you're roaming. I'll cover that here, too.
REVIEW AND MONITOR YOUR DATA PLAN AND USAGE It's smart to occasionally review your data plan to check to see if a different plan is available that may suit your needs more effectively. It's also a good idea to check your usage a few times a month to make sure you're not exceeding any data limits.
Your best bet is to set up an account at www.verizon.com. Unless things have changed since I did it, you'll have to chat with an online representative to complete the process. The reason for the extra intervention (in my case anyway) was because Verizon required that I input a temporary passcode when creating my online identity, and the only way to get one then was through text messaging. Because I couldn't get texts on my Xoom (without third-party software that may or may not have ...