I am a teacher with ADHD. What, if any, rights do I have? Where should I look for information on handling this successfully in the workplace? There are modifications for students but as far as I know nothing for teachers.
You are seeking information on your right to accommodations as a teacher with ADHD. Assuming you work for a public school, your rights are determined by the Americans with Disabilities Act, Section 504 of the Rehabilitation Act, state disability laws, and your union contract.
As a general matter, people with ADHD that are otherwise qualified for their job are entitled to receive reasonable accommodations in employment when needed to address the impact of their ADHD on their ability to successfully perform their work. The Equal Employment Opportunity Commission has regulations and explanatory material on the rights of people with disabilities in relation to employment.