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

Amazon now offers free Kindle versions of Boundless textbooks in a variety of subjects!

Generally Useful Sources

 * 4Tests.com - free practice tests for CLEP exams.
 * Allpsych - free ebooks on psychology.
 * Annenberg Learner - several video series covering sciences, mathematics, social sciences, and humanities.
 * Education Portal - free videos with practice quizzes that are geared towards the various CLEP exams.
 * Flashcard Exchange - self-explanatory
 * Free CLEP Prep for advice on preparing for CLEP/DSST/etc tests and study guide sources.
 * Free University Project Page - similar to Free CLEP Prep.
 * HippoCampus - free instructional videos in different general ed subjects.
 * Homeschool College USA -  " designed for homeschooling high school students who would like to tailor their courses toward using college-level exams to earn college credits while completing their high school studies".  Useful information for traditional high school students and others as well.
 * InstantCert Academy - flashcards for most CLEP and DSST exams, plus a couple of TECEP.  Costs $20/month  subscription, which allows access to Specific Exam Feedback section of DegreeForum.  Many DF members have found both the flashcards and the Feedback section to be invaluable in passing their exams.
 * iTunes U for (some) entire course lectures (video and/or audio)
 * Khan Academy - several video series covering various topics in science, math, business, art history, and social science.
 * LearnersTV - college lectures consolidated in one place
 * OpenCourseWare (some overlap with iTunes U)
 * OpenStax College - free online textbooks (available Spring 2012) for some general ed subjects.
 * Quizlet - flashcards & study games for most general ed subjects.
 * Saylor Foundation - free courses with videos, lecture notes, etc. on most general ed subjects; free Flat World Knowledge textbooks are available here in many different subjects.
 * SparkNotes - outlines and study guides for most general ed subjects.
 * The Whole Ed Catalog has a ginormous list of study guides for CLEP, DSST, and TECEP exams.
 * World Mentoring Academy (MOOC) provides all the 170+ courses for CLEP/DSST/TECEP/ECE/NYU-SCPS Study aides FREE online Academy with lectures, textbooks, G+ Hangout study groups, Meetups, Activity spaces( makerspaces, art residencies, TV/Film studio's etc), and practice tests. With over 840 courses From MIT, Yale, Stanford, FSI, UCLA, Khan Academy, NPTEL & other leading Universities.

Math

 * Education Portal - free videos and quizzes for the math CLEP exams.
 * Khan Academy -- 2000+ free videos on many topics, mostly math, grade school through linear algebra
 * learner.org -- "Against All Odds - Inside Statistics"
 * Mathway.com - good resource for seeing how math problems are solved.
 * PatrickJMT -- similar to Khan Academy
 * Purplemath - excellent resource for help in learning different math subjects.
 * /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.
 * World Mentoring Academy is a Free online Educational CMS with Mathematics Lectures, assignments forums and testing (8 - SAT-math & GMAT-math prep tests).

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