Handbook of Biological Statistics
This is a free pdf of the printed version of the online Handbook of Biological Statistics (http://udel.edu/~mcdonald/statintro.html). It covers many of the statistical tests that are commonly used by biologists, with an emphasis on choosing, applying and interpreting the right statistical method for an experiment (and relatively little math). The pdf version is formatted for print, with the banner, sidebar, and decorative figures of the online version omitted.
A spiral-bound printed version is also available for $16 from http://www.lulu.com/product/5507346 .