"To practice bhakti-yoga, one must first accept a bona fide spiritual master. Śrīla Rūpa Gosvāmī, in his Bhakti-rasāmṛta-sindhu (1.2.74-75), advises:
viśrambheṇa guroḥ sevā
tyāgaḥ kṛṣṇasya hetave
One's first duty is to accept a bona fide spiritual master. The student or disciple should be very inquisitive; he should be eager to know the complete truth about eternal religion (sanātana-dharma). The words guru-śuśrūṣayā mean that one should personally serve the spiritual master by giving him bodily comforts, helping him in bathing, dressing, sleeping, eating and so on. This is called guru-śuśrūṣaṇam. A disciple should serve the spiritual master as a menial servant, and whatever he has in his possession should be dedicated to the spiritual master. prāṇair arthair dhiyā vācā. Everyone has his life, his wealth, his intelligence and his words, and all of them should be offered to the Supreme Personality of Godhead through the via medium of the spiritual master. Everything should be offered to the spiritual master as a matter of duty, but the offering should be made to the spiritual master with heart and soul, not artificially to gain material prestige. This offering is called arpaṇa. Moreover, one should live among devotees, saintly persons, to learn the etiquette and proper behavior of devotional service. Śrīla Viśvanātha Cakravartī Ṭhākura remarks in this connection that whatever is offered to the spiritual master should be offered with love and affection, not for material adoration. Similarly, it is recommended that one associate with devotees, but there must be some discrimination. Actually, a sādhu, a saintly person, must be saintly in his behavior (sādhavaḥ sad-ācārāḥ). Unless one adheres to the standard behavior, one's position as a sādhu, a saintly person, is not complete. Therefore a Vaiṣṇava, a sādhu, must completely adhere to the standard of behavior. Śrīla Viśvanātha Cakravartī Ṭhākura says that a Vaiṣṇava, a person initiated into the Vaiṣṇava cult, should be offered the respect befitting a Vaiṣṇava, which means that he should be offered service and prayers. However, one should not associate with him if he is not a fit person with whom to associate."
(Śrīmad-Bhāgavatam 7.7.30-31, Purport)