The Beauty Brains has a good overview of oxytocin -- what it does, when and how it's produced. And they've very kindly linked to this blog!
Beauty Brains is the work of two cosmetic chemists who answer questions about beauty products, demystifying and sometimes debunking product claims. As someone who loves to browse the cosmetics aisles of the drugstore, I really enjoy their site.
They're also fellow members of Indy Science Blogs, a group of scientists, academics, journalists and science nerds. There's always something new and unexpected from our group, so if you haven't checked this out yet, well, go there!