I agree with everything Misha said concerning the skin. As for the screenshot of this skin, you can take screenshots in the world editor just like you can in Warcraft 3, they will both end up in the same folder. Taking screenshots in the editor gives you a little more control, as you can hold down shift and your right mouse button and drag it to zoom in and out, and hold down the Control button and the right mouse button to move your view left or right. You can set up a black background around the model you skined by
1) - changing the tilest to outland abyss and changing the model's movement type to "flying" that you are taking a screenshot of
2) - creating a doodad off of the Checkered cube model found in the Extra models, setting it's maximum size to 10 (1000%) and mimimum size to .01 (1%) and distorting it to creat a few walls and a floor, or
3) - importing a pure-black tilest (you know how to skin a model and upload it, this one is the easiest to do and best to work with).
if you want a different backdrop for your skinned model the 3rd option for creating your own Warcraft studio will allow you to take screenshots with any color you want, but solid colors usually look the best, as they won't distract from the textures on the model you skinned, which is the whole purpose of showing the screenshot anyways.
Hope this helps.
Approved
well lemme bombard it 
