For what its worth from someone just finishing third year. Personally I strongly prefer an "overview" book and then to learn most of the specifics by doing questions and seeing patients on the wards.
Medicine: MKSAP 4, MGH Pocket Medicine.
-I found MKSAP 4 covered most of the big topics. MGH Pocket medicine is by far the most valuable book of all. You can quickly look things up after admitting a patient to formulate a real plan and, in general, you have all the answers in your pocket.
-Keep in mind the environment of your hospital as well. Ours is all electronic medical records so there are literally computers everywhere, ie. Uptodate available at every turn.
-I know alot of people recommend Step Up to Medicine and while I do think it is a great book (and which I do own) I also think it is completely excessive and overkill to actually read during the rotation. The book is huge so you cant really carry it around with you in the hospital. When you get home you have so many other things to do like prepare your powerpoint presentation, review the literature, and read up on your patient so you can make "real" contributions to rounds the next day, and dont forget you have to sleep so that you are energized to suck up the following day. What I am trying to say here is that it is a good reference text, but not useful in your daily use. While I know it works for some I think it is very low yield.
-Case Files Internal Medicine: i dont think this is a must have so I am not listing it at the top. It is only useful as something to get your mind thinking like an internist, especially if you are far removed from step 1 or clinical medicine in general. I only recommend it for people who are crammers and can go through all the cases the weekend before your rotation starts. It is a good overview (i want to emphasize overview as this is not detailed enough to really do anything on the wards in my humble opinion. Just knowing that you treat CAP with cef and azithro is only half the battle now. Think about how you know whether it is CAP versus HCAP. Do these drugs require renal dosing? Liver failure dosing? What general bacterial classes do they cover? Dosing? PO or IV? If both are available when do you want to use one or the other?) of all the most common things you will see, but by no means is it necessary if you have a solid foundation from the first 2 years. Otherwise I would spend time during the rotation reading about your patient specifically, preparing articles/presentations, spending time with your non-med student girlfriend so she doesnt dump you for "always studying," and doing MKSAP questions.
Pediatrics: Blueprints Pediatrics, Pretest Pediatrics
-Blueprints is an excellent overview/review book. It is quite a bit longer than the other blueprints books, but if you have the endurance I recommend reading the whole book the weekend before your rotation starts. Dont try and memorize every little detail, but just try and be exposed to the most common disease processes so when you see them on the ward your mind doesnt go blank. You will learn the litte details during your rotation. After the fifth time of writing all the admission orders for a kid with croup you will have the details memorized. (Yes, I know that for IM above I said that now you need to know the details. I dont think this applies for peds as much as for IM.)
-Pretest had some good questions. Do it at your own pace throughout the rotation.
-Case Files Peds: I did buy this book and do it the weekend before my peds rotation started. However, I dont think it made much of a difference so I only mention it for thoroughness. Do this in your spare time throughout the rotation if you want, but I really dont think you will miss anything without it.
Family Medicine: N/A
-I did not use any special books for this during my rotation. I did this almost last and found that it was 75% IM, 15% OB, and 10% Peds (depends on your preceptor). Others may have more useful information for you than me.
-I was fortunate to have rotated through IM, OB, and Peds already so nothing was completely foreign to me (though I could not remember any of the details of anything), except I will say that I think the primary difference in FM vs IM is there is alot more focus on screening guidelines, preventative guidelines, immunization schedules, etc. In other words know preventative medicine.
Psychiatry: Current Clinical Strategies (CCS) Psychiatry, CCS Handbook of Psychiatric Drugs, Pretest Psych
-These two books carried me through my entire psych rotation. They have literally everything you will need to know during your rotation and they fit into your pocket. They have DSM-IV criteria, specific clinical findings to look for during HPI, and specific drugs to treat with (including dosing!). The only glaring omission (that I noticed at least) is that there is no section on adjustment disorder and the various iterations of it. I saw alot of this during the consult/liasion portion of my rotation. Overall, though, I speak very highly of both of these books for psych.
-Pretest Psychiatry: i think this book is very useful in fine tuning the specifics of each drug class and their side effect profiles. Not so useful for much else.
-Lange QA Psych: i have seen this recommended before and bought it accordingly so I feel the need to comment on it. DONT BUY IT! I feel like this book is so basic and not designed for med students. If you had psych during the first two years and paid any attention at all then you dont need this book. Dont waste your time.
-If you must have a review book of some sort BRS Behavioral Sciences is a really good quick summary of the entire field of psych.
Surgery: Case Files Surgery, Surgical Recall
-Surgical Recall is a must have for every medical student. It is particularly useful if you have not adjusted to the surgery lifestyle and, therefore, do not study for hours each night after going home. It really does have all the major points that you will be pimped on in the OR. However, ideally you do not need this book. Once you adjust to the surgery lifestyle you need to get a case list for the next day and figure out which cases you will be on (if other med students in your group). Read about those cases and patients in detail every night. I stopped using surgical recall about 2 weeks into my rotation and only pulled it out if I was switched into an unexpected case for whatever reason. This sounds really cliche but if you read a regular textbook for your cases you will understand what is happening and be able to at least extrapolate a good answer for those off the wall questions that you get asked in the OR. Surgical recall only has you memorize details which may or may not work depending on the surgeon.
-Case Files Surgery is a good book because it teaches the basics of floor management of surgical patients. Keep in mind it is only an overview, but it is more than you will get otherwise (at least for me). It will make sure you can recognize small bowel obstruction clinically, know the most common causes of post-op fever, know why surgical SOAP notes only mention whether the patient is passing gas or not, and know why surgeons really care about C Diff (NO! Its not diarrhea. Its not because it is contagious. Its not because it smells like a**. Those are reasons a medicine doc would care about C Diff. Surgeons care because the end game of C Diff is toxic megacolon, which requires surgery!!) I realize this last statement is somewhat of an exagerration, but you get my point.
Ob-Gyn: Blueprints Ob-Gyn, Case Files Ob-Gyn
-Once again, as states above, I really like both of these books for Ob-Gyn. Read either blueprints in its entirety or due all of case files the weekend before your rotation starts. Do both if you are a super stud. They are both excellent and contain 99% of what you will need on your rotation. You will quickly realize that ob-gyn (especially OB) has a very finite amount of information to know when compared to medicine, surgery, etc.
-Pretest Ob-Gyn: i also did this book during my rotation and found it only mildly helpful. I found that it really emphasizes small details which are not very useful on the wards. Having 50 questions on the subtle differences between the 100 kinds of abortions (threatened vs missed vs MAKE IT STOP) is not useful at all in my humble opinion. Having said that I did this book anyways because I am neurotic and was able to identify the 1 shelf question which asked me to choose the type of abortion.
Other: Pretest Neurology
-If your school has a separate neurology rotation (we did) then you must do this book. The best that I came across. Also, if you need a quick review of pathways, etc then High-Yield Neuroanatomy is an excellent 1 hour review of all neuroanatomy.
-If you have time to leisurely read other medical books unrelated to your rotation then you either have absolutely no concern about sucking ass to get honors or are a super stud way beyond me. Either way: please spend any additional time you have with your girlfriend, family, or PS3 (or research if you are going for a competitive specialty).
LASTLY: The best advice I can give which applies to everyone no matter how your rotation is scheduled is to talk to the people who just did the rotation! Absolutely nothing beats knowing ahead of time what questions the surgeon tends to ask students in the OR. Or knowing how an IM attending likes to hear oral presentations so you nail it the first time around. I really, really cannot emphasize this enough. Without reading anything you can look like a stud. Remember, on rotations that you are not interested in at all the goal is to do as little studying as possible and still get the best evaluation. This is the best way to do that.
I know this is long and winded, but I thought it was time to finally try and give back a little, especially when I think back to all the neurotic questions I had when I was just starting 3rd year. Hope it helps someone out there!