June 13, 2004 -- MOVE over, Casanova. Step aside, Don Juan. Out of the way, Mr. Big. Meet Ian Kerner, the author of "She Comes First: The Thinking Man's Guide to Pleasuring a Woman."

And you thought the brainy ones couldn't be good in bed. Well, here's one smart aleck who knows how to put all that book knowledge to good use.

Immersing himself (pun intended) in the complexity of female anatomy, Kerner has come up with an extraordinarily detailed how-to manual for men.

Study it like a pre-med student and you'll get toe-curling results.

"Unfortunately, most men know more about what's under the hood of a car," says the 37-year-old Kerner.

Kerner, who has a Ph.D. in clinical sexology, is forthcoming about his personal reasons for writing "She Comes First" (ReganBooks).

The author suffered from premature ejaculation for many years before discovering that the tongue could be mightier than the sword.

"Oral sex offered me a way to get beyond the malfunctions of my own anatomy and discover new ways of gratifying women as well as myself," he says. "My personal journey has been one from sexual dysfunction to sexual health."

He became inspired to write the book to help others as well. "I meet so many people who are so troubled by their sexual lives. Sexual dissatisfaction is the No. 2 reason for divorce in this country."

Kerner claims that, while his book is about pleasure, "the other message that is just as important to me is sexual courtesy: getting men to understand and appreciate female sexuality."

Many men, he says, tend to get off and then nod off. Kerner argues that a little sexual chivalry can go a long way toward keeping the peace between the sexes.

Think of Lorena Bobbitt: When she was questioned about why she cut off her man's penis, she responded, "He always has an orgasm and doesn't wait for me. It's unfair."

It's a documented fact that most men finish within a few minutes, whereas women may need 15 minutes to even get aroused enough to have an orgasm.

Kerner feels much of the problem is that most guys are in over their heads.

"When I started reading magazines like Maxim and Men's Health, I noticed that whenever they did address oral sex, it was a series of entertaining tidbits.

"And then I started looking at the bigger sex books that were out there, and to me they were like big fat cookbooks, a whole lot of everything but not specifically addressing the subject."

Kerner's book combines case studies and his own personal experiences to create the ultimate how-to, written with humor, illustrations and instructions.

Kerner, who reads from his book at the Museum of Sex on June 22, is pleased women seem to be flocking to the book.

But he's much more interested in enlightening the men of the world.

"I really want to reach the Howard Stern demographic more than anything - guys in their 20s, the frat boys.

"Ultimately, it's not about mastering an actual technique, it's about getting hip to the general idea of placing a woman's pleasure on an equal playing field as their own."