 About descriptive statistics
 About inferential statistics
 Variables
 Parameters
 Statistics
 Summation notation
 Measurement scales
 Exercises
Browse through an unbiased list of online mathematics degree programs so you can get an associates, bachelors, masters, or even certifications in mathematics. 

Types
of data by Keith Dear
Basic
concepts by H. J. Newton, J. H. Carroll, N. Wang, and D. Whiting
Measurement
and sampling (PDF) by B. Gerstman
Data display
and summary
by T. D. V. Swinscow; revised by M. J. Campbell
Elementary concepts
by StatSoft
Measurement theory
by Warren Sarle

Statistics
for the Utterly Confused
by Lloyd Jaisingh
Forgotten
Statistics : A SelfTeaching Refresher Course
by Jeffrey Clark
Chances
Are : The Only Statistics Book You'll Ever Need
by Stephen Slavin
The
Cartoon Guide to Statistics
by Larry Gonick and Woollcott Smith
Schaum's
Outline of Theory and Problems of Elements of Statistics I: Descriptive
Statistics and Probability
by Stephen Bernstein and Ruth Bernstein
Statistics
the Easy Way
by Douglas Downing and Jeffrey Clark (Contributor)
Statistics
You Can't Trust : A Friendly Guide to Clear Thinking About Statistics
in Everyday Life
by Stephen Kent Campbell, Steve Campbell, Mark V. Hall (Illustrator)
Statistics
: Cliffs Quick Review
by David H. Voelker, Peter Z. Orton
Fundamental
Statistics for the Behavioral Sciences with CDRom
by David Howell 