​Audio Book: 
Taking Control of Adult ADHD. Second Edition. By Russel Barkley, PhD
If you're already diagnosed and familiar with treatment, I recommend jumping ahead  to Steps 2 and then 4. 

ADHD Group Coaching with Psychologist Dr. Liz Gustafson:
Monday or Wednesday ADHD Skills & Accountability Groups for adults with ADHD. These small, ongoing virtual groups combine practical executive functioning support, weekly goal-setting, and accountability with connection to others navigating similar challenges.
Mondays or Wednesdays at 9am PT / 12pm ET
• 60 minutes weekly
• Maximum of 5 members
• $80/session
• Open to adults in New York and California
• Formal ADHD diagnosis not required
https://www.lgpsychotherapy.com/adhd-accountability-group

ADHD Coaching & Remote-Workers weekly group:
ADHD-Collective: When nothing holds the day in place, ADHD fills the gaps.
https://adhdcollective.com/

ADHD Psychotherapy and ADHD therapy group:
ADHD-Focused therapists. Founded by Karla Schlags, LMFT
California Integrative Counseling Center

Free ADHD Coaching and Peer Support Group:
Hosted by Carlos Prieto, Jr, ADHD Coach
https://www.meetup.com/bay-area-adhd-group-coaching/events/

ADHD YouTube Channels:
How to ADHD By Jessica McCabe
https://www.youtube.com/c/HowtoADHD

Therapy in a Nutshell by Emma McAdam, LMFT
https://therapyinanutshell.com/