I went to my local public library and the reference librarian help me find this VHS/DVD series from the Teaching Company http://www.library-teach12.com/teach12.asp
. They have numerous subjects from sciences, english, history, and business. Your local library may have some of these or may be able to borrow them from another library for you. Check with your reference librarian.
You can download some of the programs in audio format to your computer, iPod or mp3 player. These are actually university/college level instructors giving their lectures that they would give in class. These lectures explain processes and theories.
I used the VHS/DVD format of this series from my local library for my DANTES Ethics (they have numerous on titles on the different theories) and for the CLEP Human Growth and Development (Lifespan). I passed both exams. Now I am using the A & P for A & P 2 and Algebra.
If your reference librarian helps you they may be listed under the title "The Great Courses".
Hope this helps.