First, try watering the plant from the bottom. Violets can be damaged when water is left on the leaves. If watering from the top, blot any water gently from the leaves with a paper towel immediately.
When soil surface is dry to the touch, set plant in saucer of water and allow to absorb for about 30 min and discard excess water. Remove outer leaves with significant brown edges as plant grows. Use a well balanced fertilizer diluted to around 1/4 strength with every watering. Flush with plain water from the top once a month to remove fertilizer salt buildup if constant feeding.
Repot violets in fresh soil-less mix (should be fluffy, not heavy) once a year or so. If a mini or semi-mini, repot more often.
If plant appears healthy but does not bloom, it probably needs more light. Violets need bright, indirect light to bloom, such as an Eastern exposure. If window is too bright, use a sheer curtain or blinds to reduce intensity. Artificial lights can work very well.
Happy growing!