well, there are several ways to go about it and it depends on what happened and what you want to recover. you may just need a bootable OS, without knowing the details of what happened I can't recommend a Best solution
. it my be as simple as putting the drive in a nother system/ booting to a bootable os ( http://s-t-d.org/
mount the drive, a USB drive, and copy the files to a USB flash drive and you have your data or For a police investigation it my require a bit for bit copy of the hard drive.