Also see www.kellymom.com for the answers to many breastfeeding questions.
My favorite remedy is coconut oil. Put organic coconut oil on the nipples and in baby's mouth before and after every feeding until the thrush is gone.
Grapefruit seed extract diluted is also suppose to work, but its really bitter while coconut oil is sweet.
Coconut oil is also great for on the neck yeast rashes and for cradle cap.
All these things are caused by yeast in the body, and its best if mom takes grapefruit seed extract and probiotics in capsule form 3x daily to get rid of it systemically. For baby, its best just to use organic coconut oil.