Did you know?
There are several dating sim engines.
You can find an exhaustive list of the various engines and links on this page.
Useful Links
Ren'Ai Archive is a collection of 108 original English-language visual novels and ren'ai (romantic) games. Lots of stuff there, mostly freeware so have fun!
Lemma Soft forums a very big community of Visual Novels / dating sim games.
Otakuism forums another good community for Bishoujo & Otaku culture.