Detection and Characterization of Extrasolar Planets: Methods of Planet Detection -- Planet-Forming Disks -- The Currently Known Extrasolar Planets -- Radial-Velocity Surveys -- Gravitational Microlensing -- Planetary Transits and Searches for Light Reflected by Planets -- The Effects of Atmospheric Turbulence on Astronomical Observations -- Introduction to Optical Interferometry -- Astrometry with Interferometry -- Nulling Interferometry -- Appendix. Physics of Substellar Objects Interiors, Atmospheres, Evolution: Introduction -- Our Giant Planets as a Basis for the Study of Substellar Objects -- Basic Equations, Gravitational Moments and Interior Structures -- Equations of State -- Opacities and Heat Transport -- Interior Structures of our Giant Planets: Numerical Integrations and Results -- Evolution of Giant Planets and Brown Dwarfs -- Spectra and Atmosphere -- Pegasi Planets. Protostellar Disks and Planet Formation: Introduction -- Observations of Protostellar Disks -- Theory of Disk Structure and Evolution -- Dust-Gas Dynamcis -- Growth of Planetesimals to Planets -- The Formation of Gas Giant Planets -- Planet Migration.