This document contains resources to help Head Start programs that serve pregnant women and families with infants and toddlers develop a performance measurement plan and carry out data collection that will support their continuous program improvement efforts. These performance measures activities should build upon existing screening and assessment activities required by the Head Start Program Performance Standards. This document discusses the importance and development of a comprehensive plan and presents profiles of instruments that may be useful to programs. Because we anticipate that it will be used under different circumstances for different purposes, we present the background information in a book format, and the entire document on a compact disk, to enable users to search for the sections and measures that apply to them. This format will also support the continued evolution of the document, which is intended to be a “living” document to which information on new instruments can be added, through which new tools and approaches can be shared, and in which other resources that individual programs find useful can be compiled. These materials will be most useful when used in consultation with an assessment expert.