This paper provides an introduction to methods in archaeology that utilize light isotopes for helping to determine diet and heavier isotopes for information on mobility and provenience of specimens. The common isotopic systems of carbon, nitrogen, oxygen, strontium, and lead are described in terms of basic principles, specifically with references of human bone and tooth enamel. Isotopic analyses of carbon and nitrogen in collagen for past diet provides information on certain food types (e.g., C₄ plants, marine resources, freshwater fish) and trophic level, while the analysis of oxygen, strontium, and lead can provide information on local vs. non-local origins, mobility, and place of origin. Analysis of tooth enamel provides information on childhood contexts, and the analysis of adult bone provides information on the later years of life. This paper is intended to provide the methodological background for the isotopic analysis of human and faunal materials from the Viking colonization of the North Atlantic.