Commercial Advanced Maneuvers

USU Operations Manual (Read this to understand exactly how to fly each Commercial ACS maneuver specific to the DA40 and USU ops)

Commercial ACS (Read this to know exactly what Is free game for a DPE to test you on during an FAA check-ride)

NTSB 830 (Accident vs. Incident)

91.211 Supplemental Oxygen

POH Chapter 7: Description of the Airplane and it's Systems

PHAK Chapter 15: Airspace requirements

91.155 Basic VFR Weather Minimums

Ramp checks (Personal Docs, Airplane Docs, Required Inspections)

PHAK Chapter 8: Flight Instruments- Specifically Pitot Static System (blockage errors, 6-pack vs. G1000)

Flight planning (situational, airspace, weather mins, TOC)

PHAK Chapter 16: Navigation (specifically diversion pg. 16-34)

G1000 Diagram (what fails with AHRS and ADC fail)