New York- It's the stuff of fantasy: two beautiful, blond porn stars size each other up, and then vie for your attention. Except in the case of Jenna Jameson and Candida Royalle, the competition is not on film or online, but in the bookstores.

Jameson's "How To Make Love Like a Porn Star," is currently in its third week on the New York Times and other best seller lists; Royalle's "How to Tell a Naked Man What To Do" is set to appear in bookstores next month.

This is one case in which you really can't judge books by their covers - or their titles. While Jameson's hefty tome, from Reganbooks, is a nonlinear, tongue-in-cheek autobiography that both celebrates and laments the adult star's troubled life, it actually offers no advice to the love or sex-lorn.

Royalle's similarly prescriptive title, on the other hand, is a straightforward how-to book, advising its female audience on how to improve their sex lives. While Jameson's book includes fashion-magazine-quality color photographs, as well as scribbled diary entries and lists, Royalle's tips are offered in a more traditional anecdote-plus-advice manner. Topics include "set the stage," "bring in props" and "wardrobe check." There are no illustrations.

The books reflect the different personalities of the two stars. Royalle is as much a sex educator as an actor; in recent years she has become most famous for her Femme productions, a "woman friendly" adult entertainment company. Jameson is best known for her steamy videos, as well as her on-air relationship with Howard Stern.

So far, "How to Make Love Like a Porn Star" has received more favorable notices than just about any prescriptive book - on sex or any other topic - which tend not to get reviewed at all. And sales in one month of publication have reached 150,000. There have been six printings.

Fireside executives will not reveal the first printing planned for "Naked Man," but promotional plans include tapping into Royalle's own Web site and speaking engagements. There will also be promotional material sent to anyone who orders any of Royalle's products, including films.

Books in general, and how-to books in particular, are mostly geared to female buyers, and Royalle's is obviously no exception.

The target audience for "Naked Man" is "100 percent women," said Touchstone Fireside's Cherise Davis.

Regan said that only about 40 percent of the people who have shown up at Jameson's readings are female: "This book is about the pornification of our culture. And that doesn't have a gender," she said. "Our book works because it is not a stupid sex book."

Royalle's people have similar enthusiasm.

"Candida's book is explicit without being pornographic," countered Davis.