Start with high-confidence critical & icu nursing books, then narrow by subgenre or adjacent topics.
Critical Care
Theresa Brown
Transformative Nursing in the NICU
Mary E. Coughlin
Pediatric CCRN Certification Review
Maryann Godshall, Emily Warren
Adult CCRN Exam Premium: Study Guide for the Latest Exam Blueprint, Includes 3 Practice Tests, Comprehensive Review, and Online Study Prep
Pat Juarez
Critical Care Nursing Made Incredibly Easy
David W. Woodruff