The USB port on the iLiad is for memory sticks. The USB port for connecting to a computer is on the "travel hub".
The iLiad is running Linux and you can load your own apps on it if you get the developers package, however it isn't a good choice for learning Linux because most Linux applications won't run on a device this resource limited. The non-standard nature of E-Ink displays is also a issue when porting Linux applications to the iLiad.
There have been reported issues with some WiFi configurations, see WPA fix