He turns his mind away from those phenomena, and having done so, inclines his mind to the property of deathlessness: 'This is peace, this is exquisite — the resolution of all fabrications; the relinquishment of all acquisitions; the ending of craving; dispassion; cessation; Unbinding.' (Jhana Sutta - Thanissaro Bhikkhu translation)
In terms of practicing, Sharon Salzberg's Loving-kindness is very accessible. She lays out the instructions pretty simply and clearly. I liked Alan Wallace's The Four Immeasurables for a further discussion of them.