These online books are a great way to review, and also to learn new material. The first set of links are mainly introductory, partly at the level of our Statistics 251 course, but several of these books also include additional material.
: An online book by Jan de Leeuw of UCLA. Includes material on multivariate statistics.
from the Cornell University Office of Statistical Consulting. An archive of electronic newsletters that cover a variety of topics. Some newsletter titles are: Assessing Logistic Regression, Analysis of Complex Surveys, Tree-Based Regression Methods, and Bootstrap Estimation of Variability.