The earth's interior was described and explained accurately in the movie.
We know the structure of Earth's Interior from observing the behavior of seismic waves generated during earthquake activity. The main divisions are the: crust, mantle, outer core and inner core. The mantle is further subdivided into zones based on seismic wave activity, these zones being the: upper mantle, asthenosphere and the stiffer lower mantle.
It is true that the outer core is a rotating fluid, the composition of which is most likely dense iron and nickel. The inner core is solid.
Click the image to the left to enlarge it in a new window. (Image Courtesy of: USGS)