First all, I am new to Gumstix and intend to use Gumstix for my research.
I had just bought a Verdex Pro XL6P, a breakout-vx and netpro-vx expansion boards.

I tried to connect Gumstix for the first time to my laptop using the USB mini-B port on the breakout-vx board in the hope of following the Quickstart guide in Gumstix.net.

However, I could not find /dev/ttyUSB* despite it being connected to my USB port. I tried lsusb and could not locate Gumstix in the list. Trying to use Kermit or Minicom doesn't help since I don't know to which port my Gumstix is connected. 

Now, I am completely clueless... if you can enlighten me, it would be much appreciated. Thanks!