Here are some tips on how to look after your nails.
First of all, I would recommend a manicure at least once every 2 weeks to start. Have your manicurist use or purchase a product called Nail Envy by O.P.I which is a nail strengthener for sensitive and peeling nails. They will also trim your cuticles and you will be less apt to chew at your nails. Keeping your nails filed also helps so you don't have any ragged edges.
Nail growth starts from the root to the tip of the finger, with additional nutrition supplied from the nail bed, so it's important to condition your cuticles with some kind of cuticle oil. There is a product called Healthy Hoof which is an intensive protein treatment that you massage into nails and cuticles to nourish and moisturize. Apply a hand creme over top, and wear gloves to bed at night.
Fingernails grows around 3 mm or 0.1 inch a month, and grows through completely within 3 to 6 months, so you will need to be patient. (Brewer, 24)
Source: The HUMAN BODY A visual guide to Human Anatomy. Dr. Sarah Brewer. 2009.