You posted in the iPad forum instead of the iPod forum. To get answers to your question, next time post in the proper forum. See https://discussions.apple.com/index.jspa I'll request that Apple relocate your post.
Some of this is applicable to iPods.
Report to police along with serial number. Change all your passwords.
These links may be helpful.
How to Track and Report Stolen iPad
http://www.ipadastic.com/tutorials/how-to-track-and-report-stolen-ipad
Reporting a lost or stolen Apple product
http://support.apple.com/kb/ht2526
Report Stolen iPad Tips and iPad Theft Prevention
http://www.stolen-property.com/report-stolen-ipad.php
How to recover a lost or stolen iPad
http://ipadhelp.com/ipad-help/how-to-recover-a-lost-or-stolen-ipad/
How to Find a Stolen iPad
http://www.ehow.com/how_7586429_stolen-ipad.html
Apple Product Lost or Stolen
http://sites.google.com/site/appleclubfhs/support/advice-and-articles/lost-or-st olen
Oops! iForgot My New iPad On the Plane; Now What?
http://online.wsj.com/article/SB10001424052702303459004577362194012634000.html
If you don't know your lost/stolen iPad's serial number, use the instructions below. The S/N is also on the iPad's box.
How to Find Your iPad Serial Number
http://www.ipadastic.com/tutorials/how-to-find-your-ipad-serial-number
Cheers, Tom 😉