Due to its small size and high ionization affinity, lithium exhibits excellent diffusion properties making it a proper candidate for intercalation ion batteries. We briefly review the experimental surface science studies on the diffusion of Li on solid surfaces, including our own work, and the first nm-scale studies of Li intercalation. Particular emphasis has been placed on the presentation of the surface science approach including the thorough preparation of the substrate surface in UHV, the control of the surface structure and chemical composition before and during the experiments, and the critical quantitative consideration of external factors such as temperature, electric or magnetic field, or the presence of reactive gases. Using Li as an exemplary case, typical methods and experimental procedures employed in surface diffusion studies are presented, that may eventually lead to a better understanding and further improvements of the transport properties of adsorbed and intercalated Li.