I used to carry around Tarascon's Internal Medicine and Critical Care pocketbook. Don't anymore, since I'm down in the ED 100%. (Although I do keep their Adult EM book in my pocket).
Marino's is good. That's really about the only good ICU book out there. Its lengthy but if you ever have time, go for it.
Also I would suggest reading Manny River's Early Goal Directed Therapy for Sepsis article.
Q