I've used that book to determine numbers for any aircraft I plan on flying repeatedly.
I thought the guy was insane the first time I read it. Then the light went on. It's a staple on my book shelf now
Edit: I'm going to expand.
The cheat sheet he published for your plane is a place to start (he wasn't flying your plane). The first number you generally come up with is the number you would use in a hold, or to fly an approach (if ATC isn't hounding you to keep your speed up).
As an old example, I was taught to fly a C172 using 1900 rpm and trim level, no flaps would produce 80 knots. There's your first gift. You can lose your airspeed indicator and not be even slightly concerned because if you can set power to 1900 rpm and trim for level flight you already know you're at 80 knots. You're at the top of the white arc so flaps are okay. Nice, right? Full power and not touching flaps gets you (about 500 fpm up), at real close to 80 knots.
With the retract planes he gives you another gift: The inability to land gear up.
Using your chart you are finding that level flight value with 18" MP, 2350 rpm producing (he says, YMMV) 100 mph. That's not your cruise speed it's a lower speed used to help you fly stabilized approaches. Really, really stable. Lazy. Easy. IFR is hard enough, and mastering his theory makes it so you can concentrate on navigation and enjoying the ride.
And now I realize that his chart is not for an RG, but all is not lost because you really wanted to do this anyway.
If it were for an RG then all you would do for a 500 fpm descent is drop the gear and not touch the power. You leave a hold (assuming people still fly holds) at the fixed speed, fly to the intercept localizer and then when the glide slope comes in you lower the gear and don't touch the power. Missed approach? Gear comes up and the plane flies level. You've got a few seconds to declare you are missed and get your head in the game for the next lap. Now, increase power to your 500 fpm number (23" MP and 2350 rpm from his chart) and the plane climbs at (basically) the same speed.
Now, depending on the wing location and engine thrust line the numbers are super simple. In the C172 you can get 80 knots level, 80 knots descending at 500 fpm and 80 knots climbing 500 fpm with three power settings. If you look at his table you published you'll see the same power setting used for cruise descent as for level flight flight at the approach speed. From cruise you reduce power and when your target altitude is reached you just trim for level flight and don't touch the power.
I'm going to suggest you look over his pages for the Bonanza so you can see how he uses the gear properly. Then grab a companion to write stuff down and time while you fly.
You'll learn a bunch, including when to suck the gear up. His book is quite correct that at the "oh crap, go around" speeds the gear hanging out is probably not as big a deal as we were all taught when getting our complex endorsement. Some exceptions are planes like the Cardinal RG which was the first plane I did this for. The nose gear door is a big barn door right behind the prop and it was a noticeable improvement in climb rate to get rid of the gear as soon as practical. The 182 RG doors are different and the results will reflect that. I flew a 182 RG a bunch before I read the book.
