An excellent beginning college course from Deakin University. Includes info on surveys and sampling.

RAT-STATS is a free package of statistical software tools designed to assist the user in performing random samples and evaluating the results. The goal behind RAT-STATS was to develop valuable analytical tools that could be easily used by auditors. From an initial start with four appraisal modules and three utility programs, the package has grown to include seven modules to generate random numbers, sixteen modules to appraise sample results, and four modules providing data related utilities.