Volunteer at a hospital pharmacy , steal/ask for copies of their handbooks (the ones sitting in shrink wrapped stacks somewhere of which the employees all have copies already). Healthcare information companies and drug companies give out tons of free **** to hospitals at least in my experience. Over summer internship I was able to pick up a couple handbooks of antibiotics, IV admixture handbook, and top 200 brand-generic handbook. Pretty nice stuff. Also your school may have freebies like that either as part of student organizations or as part of orientation. I would recommend waiting. The amount of resources available to you will astound you in pharmacy school (through the medical/pharmacy library), and you will have more effective ways to learn the material at that time, especially since you will be working on building the knowledge's context in your head from the classwork.
For now, just check this out
http://quizlet.com/2198288/top-200-rx-drug-list-brandgeneric-drug-class-flash-cards/
Or go peruse your local medical library and see what catches your eye.
Tbh, the most helpful school related thing pharmacy employment has taught me is standard doses. Packaging thousands of lisinopril 10s and amlodipine 5s , etc, you get to know the routine doses used, which can come in handy just having the number be slightly familiar in your head when youre on that exam, etc.