I'm a breastfeeding helper and keep seeing all sort of questions asked about breastfeeding.
These are great reference for any problem...
kellymom.com (American site, evidence based and comprehensive, includes bottlefeeding tips for expressing mums and any problem you can think of)
www.breastfeedingnetwork.org.uk (they have a drug line in case you are taking medicines and what to make sure you're ok, plus good swine flu info).
La leche league's Book of Answers, it has any problem covered, including unusual subjects like breastfeeding and cancer (plus lots of other illnesses), breastfeeding after cosmetic surgery...
Try them and see!