How to compute the electric field inside a dielectric volume?!

Dear all!
I would like to compute the electric field inside a dielectric volume? How should I do it? is it possible to use the capacitor model? (any references ..... please highlight them they are very needed )

Kind regards!

In a dielectric the E field is the same as in the vaccum divided by the dielectric constant ε_r. Then the problem is just to calculate the electric field inside a volume. You can refer to standard university physics books e.g. University Physics by Sears or Physics for scientists and engineers by Tipler for examples on simple volumes.

still don't understand ....the fact that there is no free charges in dielectrics is confusing me!