We perform molecular dynamics simulations of molecularly thin (approximate to 4 nm), binary hydrocarbon films adsorbed on the basal plane of graphite. Specifically we study the structural, dynamic, and thermodynamic properties of liquid benzene/n-heptane mixtures for different mole fractions. The intra adsorbate and the adsorbate-substrate interactions are described using a phenomenological force field, which is carefully parameterized via the temperature dependence of the densities and diffusion coefficients of the pure bulk systems and their mixtures. The interaction with the graphite surface is parameterized by comparing experimental and calculated isosteric heats of adsorption. The foremost quantity, which we calculate, is the adsorption isotherm, i.e., the surface excess concentration as a function of the benzene bulk mole fraction, at T = 283 K. The latter, which is extremely sensitive to the parameterization, is in quite reasonable agreement with the experiment. Along with the isotherm we compare the surface-induced ordering of the two components in terms of order parameter profiles. In addition, the dynamical behavior of benzene on graphite at monolayer coverage is examined, including the experimentally observed liquid to-(root 7 x root 7)R19 degrees solid transition.