Parts arrived. One of the IMUs was missing. I contacted SparkFun and they're sending a replacement. I did lots of soldering.
I connected the XBees to my computer using the USB dongle. XBee's are interesting and powerful devices. We're using the Series 1 module, which can do point-to-point, point-to-multipoint, or peer-to-peer. For now we're just using point to point. Using a AT command (via serial terminal), I set the network identifier to 1618 and left the channel at 0x0C. I set the local (controller) module's MY to 0 and DL to 1. I set the remote module's MY to 1 and DL to 0.
Using an Arduino, I established wireless serial communication between my computer and... my computer! Albeit, two different serial terminals on my computer. It's pretty neat.
Over the next week, I'll work more with the XBees and possibly the other components. There won't be a work day this week because of a school function.