it's up to you, if you're exclusively latching, you don't need to pump to keep up supply, but if you miss a latching then you should pump to ensure that your body knows that there was a feed. for myself, i was exclusively latching, so i didnt pump after feeds but just latch on demand according to bb's needs.
some more info for you on healing sore/ cracked nipples,
During the nursing session
* Breastfeed from the uninjured (or less injured) side first. Baby will tend to nurse more gently on the second side offered.
* The initial latch-on tends to hurt the worst - a brief application of ice right before latching can help to numb the area.
* Experiment with different breastfeeding positions to determine which is most comfortable.
* If breastfeeding is too painful, it is very important to express milk from the injured side to reduce the risk of mastitis and to maintain supply. If pumping is too painful, try hand expression.
Between nursings
* Keep nipples exposed to air when possible. When wearing a bra, use fresh disposable pads (change when damp). Some mothers use breast shells to protect the nipple from the dampness and friction of the bra.
* If there is a specific injury--like a bite--cold compresses (ice packs over a layer of cloth) may help: 20 minutes on, 20 minutes off; repeat as needed.
* Ibuprofen (Advil, Motrin) or acetaminophen (Tylenol) is compatible with breastfeeding.
* Once a day, use a non-antibacterial, non-perfumed soap to gently clean the wounded area, then rinse well under running water. Using soap on the nipple area is not recommended unless the skin is broken.
http://www.kellymom.com/bf/concerns/mom/nipplehealing.html