The author reviews basic forces on moduli that lead to their stabilization, for example in the supercritical and KKLT models of de Sitter space in string theory, as well as an AdS(sub 4) x S(sup 3) x S(sup 3) model the author includes which is not published elsewhere. These forces come from the classical dilaton tadpole in generic dimensionality, internal curvature, fluxes, and branes and orientifolds as well as non-perturbative effects. The resulting (A)dS solutions of string theory make detailed predictions for microphysical entropy, whose leading behavior we exhibit on the Coulomb branch of the system. Finally, I briefly review recent developments concerning the role of velocity-dependent effects in the dynamics of moduli. These lecture notes are based on material presented at various stages in the 1999 TASI, 2002 PiTP, 2003 TASI, and 2003 ISS schools