They like to be a little crowded in their pots. Leaves should be thick, strong and fuzzy with very few nicks or tears. If it isn't already in bloom, look in the crown of the plant for developing buds. They do their best in strong indirect light. In winter, they can even take the direct afternoon sun.
African violets grow and bloom very well under artificial lights.
They like to be kept moist, but can dry out slightly between watering. Care should be taken when watering to avoid getting the leaves wet. Either water from beneath the leaves or from the bottom of the pot. Try to use room temperature water. African violets need good drainage and shouldn't sit in water more than a half hour.