Here: https://github.com/XargsUK/awesome-adhd
My personal choices are...
• Russell Barkley, phD
• Dr. Tracey Marks
• How to ADHD
• ADHD ReWired
• ADHD Experts
And you asked for sources, but these tools are great...
Apps
MyTherapy Pill Reminder: Notifications are annoying enough for me to take my pills.
Alarm Clock for Heavy Sleepers: I am not a heavy sleeper. I use it as my default alarm because it is highly customizable and it lets me snooze whatever time I need to snooze from a list of options I decide. Also, you can have alarms with different behaviors.
Bitwarden Password Manager: It's impossible to remember all your passwords nowadays...
Everyday objects
Clever Fox Pocket Weekly Planner: Before, I had reminders and to-dos everywhere (phone notes, post-its, to-do app, alarms...). Now I only use this notebook. Everything is here, from "do laundry" to "Friend's birthday". It's been very helpful.
Fidget cube from Antsy Labs: It's the original one! It's nice.
Loop Experience Plus Earplugs: Expensive, but effective and comfortable.
This, and a minimalist lifestyle are helping me. I share it, just in case.
⚠️ By the way, learning about ADHD is chaotic because people have different takes on it. There's the "I am a researcher, an expert, and all my years of study have let me to conclude that ADHD is not what the DSM tells us but something different, similar but different" (e.g. professor Russel Barkley). There's the "ADHD is what the DSM says because that's the experts' consensus. If we discover something new via sufficient evidence, it will appear in future editions of the DSM. Of course there are other things to say about the disorder, but they are too new and need more research" (e.g. Dr. Tracey Marks). And then there's the "ADHD is not even a disorder, it is just a brain that's different from the average brain. ADHD is therefore not understood by psychiatrists but by people who live with it, and we say that it resembles the description from the psychiatrists but it has additional traits" (e.g. the neurodiversity movement).
Sorry for the long answer! I hope it helps.