Maybe Tuffshot will chime in. However, he is on the road all the time nowadays. I got my temps but never took the driving test. Stupid on my part. Honestly? Grab the book. Read it. Lots of it was common sense to me but I have been around trucks in the National Guard, Fire Department, and thru work a lot. You are half my age, so I would imagine some of the stuff I picked up over the years might not be stuff you have seen. Then again, I don't know how much you have been around trucks and such. You could easily know more about it than me.
What I found which helped me most was the details. Things such as tread depth and details on numbers, etc. You might know the answer but they may have several choices very close. Ex. Say you have tread depth choices and one is 5/32 and the other is 7/32. Not much difference, but if you read it the week or night before, there is one question you get right instead of missing.
It seemed like there were a ton of questions that were right in the book. It is an easy read and if you have decent reading retention skills you will be fine. My reading retention isn't the best, but I passed.