Loction of the sd card

I am installing Ubuntu on beagleboard-xM. I am using host computer with ubuntu operating system. By what command we will know the location of sd card?

Please read this book and try some of the commands:
http://linuxcommand.org/tlcl.php

It can save you many hours and many headaches.

For the location on the USB bus:
  lsusb

For the location on the filesystem:
  mount
  df

My best regards
Paulo Ferreira