Russel Barkley has some great books. I also like Ned Hallowel. They present a fairly sane, clear, practical perspective on what ADHD is and what living with it is like.

Stimulants do tend to work differently on people with ADHD than on the general population. It's mostly due to executive dysfunction which is largely exacerbated by poor regulation of dopamine/norepinephrine signaling. When you add stimulants, the signal to noise ratio improves and the dopamine baseline looks more typical. This is a great help in getting a brain to act on intentions.

In a typical person, these pathways are working well enough already. Add stimulants and the dopamine baseline is simply raised, more than it should be, which is problematic. What goes up must come down, and low dopamine feels bad. It's also a high risk place to be if you feel like the stimulant will fix it (and it will, temporarily). That's where addiction comes in.

Stimulants do effect everyone differently though. They don't help some people with ADHD. There's no single universal solution.