We discuss dipolar bosons trapped in single layer and multilayer optical lattices and study quantum phases stabilized by the long range dipolar interaction. Such systems can be realized experimentally by ultracold samples of polar molecules. We have observed solid, supersolid and pairing phases. The latter can be stabilized in the presence of a mixture of atoms and polar molecules, and in multilayered systems. Our results are based on quantum Monte Carlo simulations and are exact in a statistical sense.