The Pocket Guide to Diagnostic Tests is an excellent resource for the wards. (link is to reviews)
Authors: Diana Nicoll, Stephen McPhee, and Michael Pignone
Contents
Basic Principles of Diagnostic Test Use and Interpretation
Laboratory Procedures in the Clinical Setting
Common Laboratory Tests: Selection and Interpretation
Therapeutic Drug Monitoring: Principles and Test Interpretation
Microbiology: Test Selection
Diagnostic Imaging: Test Selection and Interpretation
Basic Electrocardiography
Diagnostic Algorithms
Diagnostic Tests in Differential Diagnosis
Nomograms & Referene Material
This short content list doesn't do the book justice though. Give me some time to flesh out all of the subtopics and include them on here.