Did anyone actually enjoy studying pharmacology during the 1st and 2nd year of medical school? One of the best resources you can have during your 3rd year rotations and into 4th year, internship, residency, and beyond is solid pocket medication and prescription reference. Epocrates is the most widely used pocket reference and I can say from personal experience, it is a MUST HAVE. There are many other apps, and some are good (LexiComp) but none are as good as Epocrates.
Set up is simple, download the app to your hand held device and the rest is self explanatory. There is a free version and a pay version. Even the free version is very good. However, your school likely has a tie in with Epocrates which will allow you to obtain the full version for free while you are in school. Ask your administrators to provide this service if they do not already do so.
The Epocrates site provides the free download for Apple, Blackberry, Palm, Android, and Windows Mobile devices