(From most introspective and least time-intensive to most community-oriented and potentially time-intensive.)
Mind-Reader: Simply reflect on the themes of the book and select a focus for positive intention. Then offer or practice the intention for whatever period of time feels right. Usually, it takes at least 30 iterations to develop a habit, so - if your intention includes building some sort of awareness that endures in your daily life - allow yourself to practice imperfectly for a while until the intention becomes a part of you.
Light-Seeker: Remove something from your life as a result of reading the book. A 'bad' habit, unnecessary "stuff", or a draining or dysfunctional relationship might all be fodder for action.
Inquirer: Choose a topic related to your book and spend a few minutes or hours on the interwebs or at your public library researching it. Then summarize and share what you learned with someone.
E-Hero: Research organizations making positive change in the world related to your book. Offer them a donation or volunteer your skills.
Adventurer: Seek out a local place, person, or organization related to your book. Visit them, then share what you learned with someone.
Skill Builder: Add to your wealth of talents by trying a new skill or activity in relationship to the book you read. Or re-commit to practicing a current skill toward your 10,000 hours!
Community Connector: Go out and help a community group related to your book.
Got an idea for a role you don't see here? Contact me at ActionReaders@gmail.com and I'll add it!