I loved ID. I found frequent review helpful, as well as studying out of some of the texts aimed at medical students. Really know your bugs, then know your drugs. ID knowledge will be helpful no matter where you work and you will find if you know it well, it can be very valuable as few healthcare workers have as much ID in their curriculum as pharmacists. IDSA guidelines are also awesome for actual practice as a pharmacist so be sure to be well acquainted with those. If you rotate at a hospital they likely will also have specific ID recommendations based on local susceptibilities, so be sure to locate that right away so you can know your specifics well.