I will be frank. If you pick and choose chapters from the book without reading the whole thing first, the only fast results you see will be constant failure.
Ask any good cook or chef - they will tell you that the safest knife in the kitchen is the sharpest one. It's the one that has been honed so finely it gives you meticulous control. Despite it's incredibly sharp edge, it is stable and predictable in your hand.
This is your GTD. You must make sure your method is sharp and honed. You cannot have a reliable system if you haven't put in the work to learn the system in the first place. It may seem counter-intuitive to put down the task lists until you've completely read the book, but trust me. What you think is time spent being productive is actually time wasted half-attempting productivity and failing. Stop working, read the book in a day or two, and then approach your work again. This is actually the faster and most productive method, even if it means a few days of "not working." You are working. But instead of attempting tasks and failing at them, you're preparing yourself to gain time in the future by doing your tasks efficiently from the get-go.
Close your computer/phone/whatever. Open the book. Read. Take notes.
Use these diddlies to mark the most important passages. Once you've finished the book, copy those passages out and stick them in your system so you can see them every day (using paper? Put them on Post-Its or a sheet in the front of your notebook. Digital? Star the tasks at the top). Do what you've gotta do to see them every day until they're instinctual. Build your system, starting simple. Add your events to your calendar. Think about each item as you add it, deciding whether it's a task, project, reference material, or trash. Process every single thing you have to deal with.
Then, and only then, start working on completing tasks.
You
must put in the work beforehand, or you will just waste time doing things poorly, which you'll have to go back and fix later. Trust me - I have been there and totally done that. It
suuuuucks.