If you go to www.trans4mind.com they have GSR meters and they have a course called
"GSR & Bilateral Meter Course" which is free. They also sell a course called "Meta-Programming" which works with GSRs where you can actually see if the negative emotion is cleared. This site has many resources and free download-able books (Transforming the Mind) and online tests that you can take. But like always, no one ever takes my advice.