Moduli spaces are one of the beauties of algebraic geometry: SETS of isomorphism classes that turn out to carry a natural ALGEBRAIC structure. Many general questions are of special interest for such moduli spaces and lead to a beautiful interplay between the geometry of the objects individually and in families. In my talk, I will try to introduce and illustrate these ideas. The moduli spaces I will discuss are those of algebraic curves --- widely studied and applied in mathematical physics, symplectic geometry and number theory. The questions I will ask about them are from birational geometry and deal with maps from these spaces to complex projective spaces.