Study Guides

Overview
The following have been listed as quality resources when studying for various CLEPs, DSSTs, or other alternative credit sources.

Written Books
The following publishers typically create study guides for CLEP and/or DSST exams, or their books may otherwise match up very well with the content from these exams. Of course, textbooks for courses are always a good source of class information as well. You can usually find older textbooks at places like Amazon or Barnes & Noble for just a few dollars. If you want to know what textbook is used for a particular class, simply look up the class syllabus online to find out, then find an older version of that same textbook for a few dollars online.
 * REA
 * Comex
 * Barron's Business Review Series
 * Cliff's Notes
 * SparkNotes

Generally Useful Sources

 * Flashcard Exchange - self-explanatory.
 * Free CLEP Prep for advice on preparing for CLEP/DSST/etc tests and study guide sources.
 * iTunes U for (some) entire course lectures (video and/or audio)
 * OpenCourseWare (some overlap with iTunes U)
 * Quizlet - flashcards & study games for most general ed subjects.
 * The Saylor Foundation - free courses with videos, lecture notes, etc. on most general ed subjects.
 * The Whole Ed Catalog has a ginormous list of study guides for CLEP, DSST, and TECEP exams.

Math

 * Khan Academy -- 2000+ free videos on many topics, mostly math, grade school through linear algebra
 * PatrickJMT -- similar to Khan Academy
 * /r/learnmath subreddit -- "Here, there are no stupid questions asked, only stupid people who don't ask questions."
 * West Texas A&M's Virtual Math Lab -- thorough explanations of College Algebra topics
 * learner.org -- "Against All Odds - Inside Statistics"

OpenCulture Resources
OpenCulture.com provides a list of over 400 freely available full-course lectures online. Most of these are provided through OpenCourseWare or similar arrangements. Among many other topic, the OpenCulture.com page lists the following that will be of interest to those pursuing alternate means of education. Each of these appears to correlate with a CLEP or DSST or similar test.

- The United States and the World Since 1945 - History of the United States Since 1945 - Geography of World Cultures - Introduction to Economics - American Literature I: Beginnings to Civil War - Literature in English: Late-17th to Mid-19th Century - Introduction to Sociology - General Biology 1 - Introductory Biology - Introduction to Biology - General Chemistry - Introduction to Chemistry - Calculus - Sets, Counting, and Probability - Fundamentals of Physics - Introductory Physics - General Psychology - Introduction to Psychology - Developmental Psychology - Marketing 321
 * - The Civil War and Reconstruction Era, 1845-1877