Applied Multivariate Statistics for the Social Sciences, "Fourth Edition"

Almost everything you need to know about how to input and read software results from someone who has actually analyzed real ( not simplified class room problems.) Very comprehensive coverage of large field. Most important, Stevens gives an insider's guide on what to avoid, what to disbelieve, and what is valid in this thicket of overlapping techniques. Great intro and guide to use of Statistical Power analysis, which is the linch-pin to planning experiments and obtaining valid results. Marvelous, and usable tables not readily obtainable elswhere that actually solve complicated problems (e.g. intra-class correlation the implicit reduction of significance.) The tables allow you to get quick results so you can short-circuit your cryptic and overweight software for basic problems. My edition, especially the tables are nearly worn-out from overuse.