As a beginner, you should definately use Blizzard's editor. Once you've learned the ropes of the editor and can produce a fully functional map, complete with triggers, custom data, etc, I would move on to World Editor Unlimited. Personally, I wouldn't use WEU by itself. I would make the terrain and doodad/destructibles layer with Zepir's or Blizzard's Editor, then use WEU to finish the map off with some custom triggers and functions. If you don't want to do all that, then you should just stick with the basic World Editor. It is, after all, the safest and most stable world editor.
