To keep your ficus happy:
Light: Ficus requires bright, filtered light. These plants can even tolerate some full sun, especially if placed in an eastern-facing window. Plants that are kept too dark will fail to grow rapidly.
Water: Keep steadily moist, but don't allow it to sit in water or it will drop leaves and suffer from root rot.
Temperature: As a tropical plant, your ficus likes it warm, between 60 and 80 F, and doesn't like extreme temperature variations. Position it away from air conditioning and heating vents.
Soil: Any good, fast-draining potting soil will likely do.
Fertilizer: Feed with a weak liquid fertilizer throughout the growing season. Ficus don't have remarkable fertilizer requirements.