I have ordered a book called Homosexualitiesfrom Amazon by Stephen O Murray. This book discusses a great length people past in present and in many different cultures who are transsexual/transgendered or would have been considered so had those terms been known.
Did you know that in the Middle East they have the Kaneth(sp?) tradition? ]Kaniths are able to see a woman unveiled and to enter her bridal chamber before her wedding. Kaniths also eat with the women and dance with them at feasts(men eat with each other and play instruments rather than dance). Kaniths are free to move about during the day, but are cloistered like Arab women at night.
Murray's book also looks at the Hirja tradition in India and in examines other transsexual groups. While this is a detailed and fascinating book. The author does tend to take the view that biological males who live and work and socialise at women only do this because they are gay men and seek male partners by dressing as women. According to Murray we transsexuals are really gay men.
Don't let that put you off this book though it is well worth reading.