Nick, Jessica Offering Camera-Free Relationship Advice

Proposed book would also share the reality-TV duo's 'untold story.'

Not only have Jessica Simpson and Nick Lachey put their marriage on display on the small screen, but they plan to do so in print form as well. The duo are shopping a proposal to publishers for a book that would advise couples on how to have a strong marriage, cameras not included.

Simpson and Lachey's book would "share [their] untold story" about how they decided to wed, how they merged their lives, and how they work to make their marriage "hotter and stronger," with the hope that they could teach by example, according to the proposal's cover letter. While much of Simpson's appeal on the show is as a ditzy blonde, she argues in the 28-page proposal for "Jessica Simpson and Nick Lachey's Secrets for a Happy (and Sexy!) Marriage" that she has a serious side too.

"I know what you're thinking: 'Jessica Simpson, what does she know about books?' " the singer wrote. "I mean, anyone who has ever seen my show ... probably thinks I wouldn't know a book if one fell on my head. But let me let you in on a little secret: I am not as dumb as I look ... [and] for those of you who think I can't read or write, know this: I have written in a journal every night for the past 12 years."

Plus the book, which has already attracted some offers, would be co-written by Us Weekly editor Lori Majewski.

In the proposal, Simpson said she feels like she's made contributions to the world via her charity work and her music, but that "the single greatest accomplishment" of her life is her marriage. She also points out that while there's an abundance of material out there about how to plan the perfect wedding (including her own previous book, "I Do: Achieving Your Dream Wedding"), the real task that people need help with is deciding whether to marry in the first place, and how to make that marriage work.

Each chapter would be broken down into a he-said/she-said split, where both Simpson and Lachey would "walk readers through our own versions of our relationship" and offer their own advice, Lachey wrote in the proposal, noting that each chapter would also include commentary from their family and friends so that it would ultimately become "two parts memoir, one part relationship-help manual." Proposed chapters include titles such as "How to Know You've Met the One," "We Did It! Now What?," "Fighting and Forgiving" and "Keeping It Hot."

Among the promised trips down memory lane, the couple promised to spill details about their courtship, their six-month breakup, how Lachey handled Simpson's decision to remain a virgin until her wedding night and recent episodes of their televised life together. And while Lachey said he won't be explicit, he promised to "speak openly" about his love life with his wife, "about our early days of bedded bliss, and about how we became compatible lovers, but only for the purposes of being of service to our readers!"

"This book is a labor of love for my wife and I," Lachey wrote. "Overall, this book is meant to be a love story. But even the best love stories have a bit of drama in them."

Though the book won't be the last collaboration the couple contemplate — Simpson and Lachey are also working on a duets album as well as a variety-show special for ABC (see "Nick Lachey Signs Deal That'll Put Even More Cameras On Him") — the proposal says that teaming up for the big screen won't be in their future. "We will never, ever do a film together," Simpson wrote in the proposal. "Nick and I were thinking the other day how it just never works. I mean, look at Ben and Gwyneth — 'Bounce' bombed. And Ben and J. Lo. Hello, 'Gigli!' Even Tom Cruise and Nicole Kidman couldn't do it with 'Eyes Wide Shut.' "

In the meantime, Simpson's video shoot for "Take My Breath Away" has been pushed back and will now premiere March 15 at 6 p.m. ET on "Making the Video" (see "Jessica Simpson Plans Breathtaking In This Skin Re-Release").