kaamasuutram

[ZYSK at ACFcluster.NYU.EDU]

Just a quite response to get you started, more to follow.
There is an edition (nothing "critical" exists) with the commentary of
Yashodhara and and Hindi commentary by Devadutta Sastri published
by Chaukhambha Sanskrit Sansthan, 3rd Edition, 1982. It should
be readily available. Several others exist in nagari from and
earlier period but they are not easily obtained. 
A decent but by no means comprehensive and critical survey is
N.N. Bhattacharyya, _History of Indian Erotic Literature_, Munshiram,
1975.
Schmidt's work underwent several editions and/or reprints. No one any
better than the other. Wezler has written something on Schmidt some
year's ago in an article on the Kamasutra, I believe. 
There is much more to say, but I am all out of time.
Good luck,
Ken Zysk