Sarah Lacy, a columnist for BusinessWeek, has spent the past several years covering Silicon Valley for insight into the world of web 2.0 startups. Her book, Once You're Lucky, Twice You're Good: The Rebirth of Silicon Valley and the Rise of Web 2.0, which comes out tomorrow, tries to get deep inside the minds of the Valley's new entrepreneurs hammering away at dot-com dreams.

Portfolio.com caught up with Lacy to get a sneak peek of what to expect.

Portfolio.com: How did you go manage to get the level of access that you needed to write this book?

Sarah Lacy: In covering venture capital for so long, I realized the way they are successful is they go based on person not company. So they pick really interesting entrepreneurs who they think will be so ridiculously determined that even if it sounds like the wrong idea, or even sounds like a bad idea, they will eventually work their way to a good idea.

Since it's so competitive to cover start-ups in Silicon Valley, I started really doing that. Every couple months or so I would try meet a couple of entrepreneurs and the ones that I thought were interesting, I'd try to spend a lot of time with and invest a lot of time in developing a the relationship.

With someone like [Netscape founder] Marc Andreessen, who's really untrusting, and really hard to get a relationship with, I spent about three years building trust with him never knowing what it was going to turn into. He was totally off the radar but I knew he was too smart and I knew he was too plugged in and I knew he was doing something interesting and I knew at some point he was going to be a fascinating story again. So it was us sitting in a coffee shop once a month and me asking him questions and him starting every answer with "off the record." It was the most ridiculous investment of time to gain trust. And the stuff he talks about in the book he's never talked about before,

With Mark Zuckerberg I first interviewed him when he was 19 or 20...I called the company and interviewed him and he answered the phone and was so brash and cocky and obnoxious, and bragging how he had gotten these outrageous terms from his investors and how no one could ever replace him as CEO and he was just really obnoxious. I got off the phone with him and thought 'Oh my God, this company's going to go under, this guy is a trainwreck." But I was still really fascinated with him . . . .

The more I started digging into who he was - he's a ridiculous onion, it's really hard to get to who he is - the more I started seeing the phenomenon the Facebook is.

And with [Max Levchin, founder of Paypal and Slide], even at the time I started writing this book, he was the most controversial person I focused on. Digg was kind of hot and Facebook was kind of hot but Slide was nowhere and no one thought it would be an interesting company. Of all the people I spent time with, Max to me was one of the most fascinating. You just don't meet people in Silicon Valley every day who narrowly escaped Chernobyl's radiation cloud. He's so extreme.

Portfolio: Who's the most difficult personality to deal with? Who do you get along with best?

S.L.: That's hard to answer, I have a love-hate relationship with all of them. I always told my husband when I was writing the book, it's like a cross between doing business in Japan and baby-sitting. They're legitimately really busy guys, but all at times were total pains in the asses about either flaking on me or waiting around for them. Marc Andreessen basically decided in 2007 that he wasn't going to leave Palo Alto and so I had to drive down from San Francisco and wait in a coffee shop and call him and be like, 'Hey, can we meet now?"

At one point Zuckerberg and I were at dinner and I asked, 'Can I record this so I don't have to take notes while I eat," and and he said 'No' and asked why, and he said, "You know, you're the only reporter I meet with and I think you should have to work for it." And he was kidding, but it's also this sense that as much as they could be difficult they legitimately were doing far more important things than helping me write this book. And I was the only reporter that got this kind of access, so I couldn't be too demanding. Though I was and they mostly complied. Taking all that into account they were great.

Marc Andreessen can be really difficult, Zuckerberg can be really difficult, Kevin Rose would stand you up constantly, if we have a meeting I'll have to call him up to 5 minutes before and ask him if we're really meeting - they're really, really busy guys.

Portfolio: I have to ask. What exactly happened in the Mark Zuckerberg interview of SXSW?

S.L.: Pretty much for an hour after the interview, Mark and I were looking at each other and 'saying what just happened.' I don't think either one of us is clear to this day on what happened. Mark's really, really awkward on stage, which is why Facebook asked me to do it, because I know him so well and he's so comfortable around me. If you watch, throughout the interview he's laughing, smiling, making jokes - he never does that on stage. And he admitted that Yahoo tried to buy Facebook for the first time, he's never admitted that. And he admitted that he fired people who had a problem with it, and drew a line in the sand and said 'We're not selling this company.' He actually busted out with a lot of news. So he and I are on stage and we think it's going great, and then all of a sudden in last 10 minutes all hell breaks loose. Part of that was an interesting test case on the opinions of the people who are these super technology early adopters. We could have done the same keynote at any business conference and it would have been incredibly successful.

Portfolio: After spending so much time with the Silicon Valley set, how do you think the caricature compares with reality?

S.L.: I think the East Coast/Wall Street idea is these are all guys who want to make a lot of money. I think the Silicon Valley perception is they're kind of brats and obnoxious and have no respect for anyone. It's kind of this idea that these guys have this gimmick, where they can come up with a site, they don't really have to build a business, and in a couple years it's worth lots of money and they've pulled one over on us. I think some of the difference is about what drives these guys, and it's almost never making money. There's such an obsession in Silicon Valley with valuation and what you make, but that has nothing to do with what you're going to buy or the money itself. It has to do with keeping score, because that's the ultimate tally.

These guys are so data driven that they feel this need to keep score. Even Mark Zuckerberg, people always talk about him being so greedy and driven by money, but he's personally turned down deals where he would have made $300 million or more. He's clearly not driven by money, because anyone else would have taken that.

I think there's an overall cocktail of things that drive these guys - legacy, ego, competition - all those things. One of the things that I tried to do in the book was figure out what their base motivation is. One reason Max is such a great example is he is I think he is the single most competitive person who has ever lived. His whole drive for creating Slide is competing with younger self who did Paypal.

Mark Zuckerberg is much less concerned with competition. What motivates him is his own intellectual curiosity about Facebook. He's of these guys who has this vision about what this could become.

Portfolio: What are some of the challenges of being a woman covering Silicon Valley?

S.L.: I started my career in the south covering finance, which is way harder, because being young and female, I couldn't get anyone to take me seriously. When I moved to the Valley I was stunned that there weren't more women, but generally felt more accepted and less like I had to prove myself.

Then Nick Denton was writing for Valleywag when started writing my book and he wrote this sort of famous piece called "Smoking Sarah Lacey" - and it basically said, 'Look, in everything that's been written about Sarah Lacey, it's never been pointed out that she's hot."

That seemed to give everyone permission to talk about appearance all they wanted from then on. It's not what you want. Anything about me immediately gets sexual and it's frustrating. There's never been a scandal about me, and there's absolutely no reason for anything to get sexual about me. But at the end of the day, all the people who are "important" in Silicon Valley, anyone who's a great venture capitalist or great entrepreneur or certainly any of the guys in the book never treat you differently because you are a woman. They've all been counted out for different reasons, and at the end of the day, the Valley is a meritocracy. I've absolutely never been treated differently by any of those people.

Portfolio: Why do you think there are so few women in the industry?

S.L.: Partially because it's so demanding. I don't have kids and I don't know if I'll ever have kids, because my job's really important and no way to stay on top of the Silicon Valley game if you're a woman with kids, I don't think. A lot of people will disagree with that. I'm at dinners or parties or talking to people or working late 4 or 5 times a week, and it's such a dynamic and fast changing seen that that's absolutely necessary.

Also on the startup front, there's not as big a pool of women who are qualified to code a site. There are definitely more men helping men in the Valley, but I think it's just because those are the people they know. It's definitely there and there's a bias but it's not a cruel or intentional bias and it's on the margins.

It'll be an interesting thing to watch because this generation of web entrepreneurs in particular isn't super techie. The web is becoming so standards based, and it's becoming so much more about media and community, the opportunity is really there for more women to take more roles.

Liz Gunnison