The old oral exam books were useful back when the oral was a simple Q&A session with specific objective questions that have clear answers. Unfortunately, the FAA has changed the way orals are supposed to be done to the "situationally-based" test. That is, instead of handing you a weather printout and asking you to read a METAR, the examiner will assign a flight to plan, and then ask you if the flight can be conducted safely -- and how you came to that conclusion. That will require you to identify and pull up all the weather data relevant to the flight, interpret it correctly, and make a sound decision based on your analysis. You'll also have to compute your aircraft's performance from the POH and compare it to airport data for runway length and obstructions to departure, as well as figuring fuel burn and fuel available, W&B, etc. IOW, no spoon-feeding of what to check -- you have to cover all the bases on your own initiative, just like you would in the real world. Likewise, the examiner will ask you if you and your plane are legal for the planned flight, not "What documents must you have with you, how long is an annual inspection good for, etc." The oral exam books often don't help much in this area.