Chapter 7 of Gil Fronsdal’s book The Issue at Hand has a short but very clear discussion of intention and the role it plays in our lives, and the value of mindfulness of our intentions in each moment. You can find that chapter here: The Issue at Hand: Chapter 7: Karma
The selection by Gil Fronsdal cited above focuses mostly on mindfulness of our intentions in each moment, and on the value of not moving through the world in a fog by just reacting habitually. To support our mindfulness of intentions in each moment it’s also good to be aware of our deeper intentions in life. Thupten Jinpa, the longtime translator for the Dalai Lama, has a 10-minute guided meditation on becoming aware of our deepest intentions, and setting intentions for kindness and compassion. You can find that meditation here: 10 Minute Guided Practice for Intention-Setting