Would like to second The ICU Book, by Marino. Very clear and readable, provides lots of background information.
Some other concepts to know, that might be helpful if going for honors:
-Concept of early goal directed therapy for sepsis, there's a classic paper on this topic that would be worth reading before starting (NEJM 2001)
-Know what your program thinks about 'relative adrenal insufficiency' and its management, the classic trials are the corticus and french trials.
-Learn what you can about managing ventilators, so couldn't find a good reference for this!