This guide by InfySim shows us how to get FreeBSD set up in a virtual machine.

Take a deep breathe and be sure that you have at least an hour of time.
We have to go a long way towards an important step.

Before going into any administration or any driver development guide, you must know how to install FreeBSD and configure it.

Just to stay in the safe side I will take the help of Virtualization software to install the FreeBSD OS.

So here goes the details about what all things you have to be with you before we start:
1.) FreeBSD OS ISO image or a DVD containing the bootable FreeBSD OS.
2.) A virtualization software
3.) A Host PC
4.) Enough time and confidence

View the full tutorial: http://www.infysim.org/2015/02/how-to-install-freebsd-os-step-by-step-guide-using-a-virtual-machine.html