A manual on sampling is presented to assist audit and program reviewers, project officers, managers, and program specialists of the U.S. Office of Student Financial Assistance (OSFA). For each of the following types of samples, definitions and examples are provided, along with information on advantages and disadvantages: simple random sampling, stratified sampling, cluster sampling, systematic (interval) sampling, dollar-unit sampling, sequential (stop or go) sampling, discovery (exploratory) sampling, multi-stage sampling, opportunity sampling, and quota sampling. Forms to aid in calculating a variety of common sample statistics are included. Three examples of the potential uses of sampling statistics and the forms by OSFA are provided, and potential problems that could arise are addressed. The forms are used to: calculate the estimate of the population variance from a sample; develop population estimates from a simple random sample; determine minimum necessary sample sizes; illustrate the use of a calculator to determine population variance; and develop population estimates. Appendices include: an introduction to the mathematics of sampling, information on sampling formulas and symbols, a 13-item annotated bibliography, and an index by primary reference or definition. (SW)