Langmuir-Blodgett films of C-60 were doped with potassium, and the doping was followed insitu by both microwave low-field signal(LFS) and electron spin resonance. The superconducting critical temperature was T-c (onset) = 12.9 = K for a nominal 14-layer film at optimum doping. The four-probe conductivity of an underdoped film as a function of temperature showed semiconducting behavior.