This site also has a BIG professional resource section:
http://www.geocities.com/breastfeedinglinks/
(Scroll down the index on the left to "Professional Info". That said, there are millions of links on the page that are helpful, but the professional section has stuff that is more directed at pros in particular. I don't know what your friend is looking for, but in addition to the LLLI page already listed, I love the
www.kellymom.com page (which is well referenced), and you can also go to
http://neonatal.ttuhsc.edu/lact/html...ns_forums.html for professional/clinical medication questions that are not already addressed in "Medications and Mothers Milk" (it is the author, Dr. Hale's, website).
PS- I would also recommend the Lactnet listserv for anyone interested in professional lactation issues:
http://peach.ease.lsoft.com/archives/lactnet.html