Details about the Crystal ball in the first episodes of Naruto I was starting Naruto and noticed the Hokage using a crystal ball to watch Naruto.

1) How does the crystal ball work?

2) What's its range?

3) What are its limitations?

4) Does any of the other characters in future episodes use it (tag spoilers)?
Much like many of the original concepts of the series (See, the Kawarimi no Jutsu), most of the "magical"-like aspects of the world has been scrapped, probably in hopes of the fans forgetting about them because they made no sense and had no explanation.

The Third Hokage's crystal ball is like that.

Not much had been explicitly explained, but it could be argued that the crystal ball is a display for surveillance cameras or other similar sensors, pre-set all over the village. This is only a wild theory though, it has no basis in the series whatsoever.