Here follows a list of actions that I took to setup and use working (independent/non surround) and gaming (span/surround) modes under: Windows 8; NVIDIA Surround 2D; and a single NVIDIA graphics card (of the right type) driving 3 (DVI) monitors.
The terms "working (independent/non surround)" and "gaming (span/surround)" modes are not official (there seems to be no standard terms), they are my own.
I'm going to write under the assumption that readers haven't used Nvidia surround before (either by being new to multi-monitor setups or coming from Matrox TripleHead2Go) and are unfamiliar with Windows 8 (Win 8).