Various time-resolved experiments on optically detected magnetic resonance (ODMR) of-single pentacene molecules in p-terphenyl at 1.8 K are described and discussed with the help of a model based on the optical-microwave Bloch equations. Intersystem crossing rates for this system are deduced from the ODMR spectra, from the fluorescence correlation function, which varies nonmonotonically with the microwave power, and from the analysis of the fluorescence recovery transients. We also discuss the enhancement of the ODMR effect on using fluorescence photons from single molecules as a time base to trigger the microwaves in fluorescence recovery experiments.