<p>I have a friend who's been out of school for 5 years and is trying to start studying for a GED. He failed the first time taking it 5 yrs ago. Now I have tried a few questions with him and it seems that he needs a lot of work. Which prep book would you recommend for this level? Im aiming for a book that isn't overwhelming like Barrons but will at least get him to a passing level.</p>