Hi Pablo,
these are so called localized clouds, which means they can be put to any location on the planet. You can try it out yourself:
1. create a cloud layer.
2. check localize in the cloud node
3. check move textures with cloud in the cloud node
4. change the coordinates under the localized cloud options on the cloud node and see what happens.
The pack ships 3 complete project files. If you want to use the clouds in a differnt project, simply save the atmosphere group and all its nodes as a clip file, and then import that clip file into your custom project.
The packs don't come with documentation, turorial or explanations, other than (sometimes) a few "note nodes" inside the project files that provide some basic orientation. You would have to bring a general understanding of TG2 before these are any useful to you.
Also, in these products we don't explain why nodes are connected they way they are, that would be a never ending story, but it's all transparent and you can explore every aspect if you so wish.
Why not just try them out? They are so much low price, I would say there is not much risk involved, is there?
Regards
Frank