Pharmcards by Eric C. Johannsen, Marc S. SabatineIMHO: Hands down the best of the pharm cards for USMLE Step one. Through and readable. If anything more information than you need. The cards have good visuals especially for anti microbials.
How to use it: These are packaged as flash cards but must be thought of as a text book. Start early and work them slowly (~10 cards/day). Take on relevant cards with the organ system you are studying at the time. As with any pharm resource for the boards focus on mechanisms and side effects. Later in your review process move on to using resources like the simpler higher yield BRS pharmacology cards and the most relevant information will be found in First Aid.