Is there any simple tutorial on how to go about this, given that I can take a bunch of screenshots at the require location? Or is there a better method?
Here's a tutorial on where the sides go, at least...
http://wiki.tesnexus.com/index.php/Photoshop_cube_maps_in_Fallout_3
It works the same way in TESV.
I do not think there's a way to automatically generate one, so... you should take the screenshots with a completely square resolution (like 1000x1000) and a FOV of 90. Also maybe set your view in the console with "SetAngle Z" to 0, 90, 180, and 270 each time to make sure it's correct, and then turn off the menus. It won't be perfectly seamless because normally in a panoramic image the edges would be curved, but in 4 separate 90 FOV images, the edges between them will have an angle. But it should be close enough that people probably won't notice in the game.