The wish to become enlightened (in order to end the mental and physical suffering of oneself and especially others) is the first step toward taking refuge.

When one takes refuge, the practitioner officially becomes Buddhist.  The practitioner takes refuge in the Three Precious Gems which are:

1) The Buddha, who is the supreme guide and enlightened teacher.  By taking refuge in the Buddha (and in those who have become enlightened like Him) you vow to abandon worldly refuge. Worldly refuge includes taking refuge in unenlightened spirits and magic.

2) The Dharma, which is the pure and untainted teachings of the Buddha.  By taking refuge in the Dharma, you vow to uphold virtuous activity and gradually practice meditation.

3) The Noble Sangha, which is the community of noble beings who are Buddhist.  This is generally the community of bodhisattvas and arhats who are disciples of the Buddhas. 

Then there is the ordinary sangha who are our companions on the path ---the community of monks, nuns and lay people. By taking refuge in the Sangha, we are encouraged to practice virtue and the dharma. We learn not put unvirtuous wishes above those of our vows and dharma aspirations.

By taking refuge, one firmly decides to enter the path of enlightenment.  One takes refuge from a preceptor who is generally a qualified Buddhist master.