there is a kaz cooke book called "girls stuff" or something like that! nappy brained atm, cant quite rememeber
I bought it for my neice when she was 12, so a little bit older, but I had a good read of it first and let her mum have a good look thru it first jic she was a bit hesitant about her reading some of the stuff (also talks thru sex, alcohol, peer pressure, drugs, eating disorders, u think of it its there!) I suggested maybe just reading a few chapters with her to start with, but my neice is pretty mature for age so we just let her run with it.
The thing I really liked about it was there is a whole chapter about talking to your parents, how to do it etc, and explaining that they are probably just as uncomfortable talking about it as they are etc, also goes into detail about why we get periods, what is happening in their bodies, what to do. I would deffinately reccomend it.
good luck, hope its not too painful for you...