If you connect your PS4 to a wired or wireless internet network, the system software update v1.51 will be available whenever you turn on the PS4, and you can just download and install it directly that way. How to Update Your PS4 to the 1.51 Software
This article has been update to reflect the newest software update version. Note: The 1.51 update just came out on November 20th, and supposedly fixes stability issues. You don't want to miss out on any sweet Sony features, plus it's mostly agreed upon to update your system whenever you can. This update isn't required, as most single-player games can be played without an Internet connection and without signing into the PlayStation Network, but I do recommend that you install it.
