I wouldn't read anything-- I would spend the next six months doing something productive and enriching that you may not be able to do over the next three years, or spend time with partner/family, or just enjoy yourself. You'll learn plenty on the go during your residency, and will have an actual context for what to read when you're doing clinical work (i.e. interesting cases, difficult cases). You have no idea where you'll be starting in July (NICU, wards, etc.)-- just have fun up to that point and be ready to learn learn learn come July!