Screw books. They are heavy, they are too big, they are outdated hours after publication. Stick to electronic references. For me, lexi-comp was my go to source. Learn how to master it, and it will be invaluable to you and your pharmacy career. Now, once I got an updated iPhone and the crack for lexi-comp doesn't work on newer jailbroken iPhones, I use Clinical Pharmacology which is just as great, if not, a better drug reference, which I get at my place of employment and at home also for free.
Stick to electronic references, and references you've heard of like lexi-comp, clinical pharmacology, micromedex, etc