I would highly recommend Mind Performance Hacks and the supporting site by Ron Hale Evans.
He has a wide range of great strategies that help you improve memory, skills (including math) and organization. While it's not specifically a Perl book, there are a number of helpful tools provided written in Perl (Like creating a random theme generator for stories which could easily be used for essays). The author is a game designer and while he makes the book fun it's VERY useful. I would be surprised if you did not find at least a few tips in there that help you improve your study habits. :)
"...the adversities born of well-placed thoughts should be considered mercies rather than misfortunes." — Don Quixote