Like you I am a virgin, and I'd say start off with something no more than 5 inches. I bought one a year or 2 ago (this is the first time I've ever admitted that!), and it was 6 inches, I accidentally nearly bought one that was 7 inches, and I'm soooo glad I didn't. The first time I used it it was so painful I was rather dissapointed, and even now I don't think I could use anything larger.