How would I go about asking a partner about his past?

I am a young gay female. I am in the middle of a relationship. It is the first time for both of us. A friend gave us a book of stories and poems, etc. about gay relationships. In a couple, there were mentions of safe sex. I never realized that sex between two women was not safe. If you could give me any details of safer sex, it would ease my mind.

I really enjoy reading your answers on these pages, but here's the question that I haven't seen addressed on your web pages or anywhere else on the Internet. Can you please suggest some appropriate ways to ask a person with whom you're about to have sex if he or she has any sexually transmitted diseases? A few months ago, I met a girl with whom I had sex... and, as I found out later, she had herpes. We did use condoms anyway, but there was still some risk in catching herpes since we didn't use condoms all the time.