Making skybox images from real world photos

Hello there!
I want to know how to take photos for making skybox from them. I’ve seen one MAP where skybox is taken from normal shots of the meadow. How to make it naturally and without visible seams? Does it have to be distorted? What field of view I need to capture and how to rotate camera? Any help would be really appreciated.

Images from map linked above:
http://images61.fotosik.pl/1142/b912880089131875med.jpg

A fisheye lens and/or knowledge on panorama sewing would help immensely.

Well considering the image is suppose to represent a sphere (because thats what a planet mostly is)

You would want to have an image of a panorama if you can make it.
You can also take 6 different pictures all pointing in the several directions, left, right, back, front, up, down.
The camera would need to be 90 degrees, which would be 360 degrees to loop around horizontally, then 90 degrees for the top and bottom as well.

If you happen to have an android phone, (like a samsung galaxy s4 or something similar) that is running android 4.4 you can download google camera.

It has an option to render out a sky sphere (basically a 360 degree panorama) You can then take that image into a modeling program and map it to a sphere and render out each side. A recent skybox that i made

https://dl.dropboxusercontent.com/u/3779442/Screenshots/sky_cloudy009_hdr.jpg

was made using this app to take the panorama then took it into 3ds max and mapped it to the sphere and rendered out the sides, and i just did some extra work on the sky with photoshop, to make sure there was no seams.