As with any deployment, if you plan on remote IT assistance, you will have to alter the "out of the box" unit with special software that allows you remote control.
By default, the XOs use DHCP to acquire an IP address. Does your access point / router provide DHCP functionality? In the XO Neighborhood view, are they able to see your access point's "circle"? What kind of authentication does your access point have (WEP2 / WPA / etc.)? If you've got these issues worked out, then the XOs should be able to obtain IP information (address, subnet, dns, etc.) from your DHCP server and they should be able to get on the net.
If you want to remotely control these units, you can create your admin user account on each of these units and SSH in to them (preferably with your private key instead of a weak password). But since the XO does not have a wired ethernet port, you will need the XO to meet you half way and get online first!
In short, I'm afraid your question is a little too broad to give specific help.
Hope I didn't make things worse! ;p