I haven't seen any tutorial that explains simply how to view your world map in 3D and check out how the poles look. There are surely other ways, but this is how i do it, and it's pretty simple.
As we all know the world is not flat-- it's round. And round and flat don't translate very directly to each other. It's very easy to accidentally create a distorted, pinched-looking polar regions without meaning to.
1) Create you map exactly twice as wide as it is tall. I believe this projection is called "Equirectangular". With this projection, vertical dimensions are not distorted anywhere on the map. I.E. if 10 pixels in a N-S line equals 100 miles at the equator, it will be the same thing at the poles. However, horizontal dimensions are increasingly distorted toward the poles. On the same map, 10 pixels will only equal precisely 100 miles at the equator. But you don't necessarily have to worry about all this.
It's the most common way spheres are textured on the computer, so files set up like this are just right for other applications, like Celestia.
2) Download Google's Free application SketchUp
3) Download and unzip this SketchUp file
This file was based on this globe by José Manuel
4) Open "Round-World.skp in SketchUp.
5) Open the Materials Palette, from the main menu: Window -> Materials
6) In the Materials Palette, double click your the planet's texture (see #1) This will expand the palette.
7) In the newly revealed lower section of the palette, use the drop-down menu (see #2) to change the texture to whatever you want.
8 ) Bask in the glory of your 3D world.
Use the Orbit tool (see #3), and the Pan tool (see #4) to rotate your world by hand, or jump to preset "scenes" with locations at the top. (see #5)
9) If you discover your poles are pinched, you can find tutorials on how to use Hugin to fix it.