Useful books for the medical intern
The Ventilator Book by William Owens: the basics of vents in about an hour.
The ICU Book by Paul Marino: comprehensive, highly readable, and provocative; covers many practical and emergent aspects of medicine.
The Only EKG Book You'll Ever Need by Malcolm Thaler: all the basics and then some in about two hours, I prefer this to the Dubin text.
ECG Workout by Jane Huff: 500+ practice strips building gradually in complexity, useful to follow Thaler with this.
Useful books for the neurological intern
Neurological Differential Diagnosis by John Patten: single author, highly readable, great schematic diagrams
Thieme Atlas of Head and Neuroanatomy: very useful illustrations, this atlas is written by clinicians
Useful books for the psychiatric intern
The Perspectives of Psychiatry by Paul McHugh and Phillip Slavney: a conceptual survey and synthesis of the practice of psychiatry - the Hopkins approach.
Psychotherapy by Phillip Slavney: a quick read aimed at psychiatrists-in-training, practical advice on how therapy is done (and should not be done).
Stahl's Prescribers Guide by Stephen Stahl: ~6 page synopsis per drug of most psychoactive medications, useful to have around.
Stahl's Essential Psychopharmacology by Stephen Stahl: helpful for contextualizing the Prescriber's Guide, an introductory text.