Śravaṇam
Hearing about Krishna, from books and from devotees.
The Bhagavad-gītā is a conversation between Krishna and Arjuna on a battlefield: about who we are, why we act, and what it means to love God. The Śrīmad-Bhāgavatam goes deeper into Krishna, bhakti and the lives of His devotees.
Śrīla Prabhupāda's Bhagavad-gītā As It Is brought these teachings to readers everywhere, and many still begin there. Study is easier, and far richer, with others: a class, a teacher, or a few friends reading together.