Tracking not possible without a anti-theft program installed prior to theft.
Like Prey: http://preyproject.com/ Even that is no help if a smart thief wipes the HDD.
The IP address is not unique to your laptop and will change when the person with your laptop uses his own internet service or a public wireless hotspot.
Your serial number never shows up online and so can't be tracked.
Make a police report and notify the laptop manufacturer it's been stolen.
The police might recover stolen property and the laptop manufacturer might notice if the laptop goes in for major repairs.