Get the book, "First Aid for the Wards". It'll tell you everything you need to know: 1. review of common conditions for IM, peds, OB/GYN, neuro, psych, and surgery. 2. how days in the different specialties are usually scheduled (when to expect morning report, prerounds, resident rounds, attending rounds, scut, conferences). 3. how to write SOAP notes and present patients. 4. how to avoid common problems/mistakes. 5. review of handbooks and ref books for each of the primary specialties. 6. what equipment you'll need for each specialty.
You should also get a few good handbooks. For IM you'll need "Scut Monkey", "Ferries", or "Wash Manual". You'll also need good drug references like "tarascon" and "sanford". However, the BEST way to go is to buy a PDA and get the following: ePocrates and ePocrates ID (both free), 5 Min Clin Consult ($60-70 but well worth it), Merck (free) and Medcalc (free). There are lots of other good books out there (go to
www.Handheldmed.com) but those are the essentials.
You should expect long, hard days...not as bad as surgery, but definately one of the more demanding rotations. The hours are usually 7am to 5pm (unless you get late admissions) and depending on your school, you may or may not have to take call with the interns. Don't get scared though, you'll get LOTS of supervision and get to see LOTS of pathology and if you're lucky, you may even get to do some proceedures. Hope this helps.