As someone who read a lot, and I mean a lot, of books about stuttering, I found most of them useless. But no harm in reading, you’ll always gain something from reading. Unfortunately, at least for me, nothing that helped with my stutter. What helped me the most is to socialize as much as possible and stutter while doing so. It helped my stutter a lot. Although I still stutter and coming close to the age of 30, but it’s no where severe as it was during high school. My advice is go out, ask every vendor you see about what they’re selling even if you don’t plan to buy. Ask strangers about directions. Ask electronic shop workers about stuff you don’t know how to work, go to a fast food place and order what you want and stutter as hard as you will. That will crush it and help you more. It’s scary and I’m still terrified when I do any of those, but it gives me a huge boost and decreases my stutter a lot. Hope this helps. Best of luck