Many people reach mid-life only to realize they’re no longer happy with their job – and perhaps haven’t been happy for a long time. They want to make a change, but they’re afraid: Quitting a job to start a business or a new career is risky and scary in so many different ways.

Jennifer and Joe Remling experienced this when they left their own jobs to go into business for themselves. So in summer 2007, the Atlanta-based husband and wife went on a road trip across America to find out what it takes to ditch a career and start again. They set out in a big silver Airstream trailer and drove across the U.S. to interview more than 40 Americans who’d quit jobs to pursue a lifelong dream.

The outcome of their adventure is a new book, “Carve Your Own Road: Do What You Love and Live the Life You Envision,” which includes highlights from these many interviews along with advice on how to make a smooth transition from the career world to self-employment. We caught up with Ms. Remling to talk about what they discovered and what advice they’d give to aspiring entrepreneurs today.

WSJ: What’s the motivation behind this book?
Ms. Remling: I ran corporate recruiting for high-tech companies for 13 years, and got a job in London. When I arrived, the guy in charge of the office said, “What are you doing here? I don’t want an American for the job.” It was a very tough experience, to say the least, and I was eventually tasked with laying off everybody in the office. I returned to the U.S. in summer 2001 and there were no jobs in technology. I was already in a bad state of mind. I realized that I had lost my identity, and I went on this odyssey of deciding to reinvent myself and doing work that is meaningful. My husband quit his job and started an architecture firm in 2004, and in 2006, I finally started my own consulting business. We began to realize our lives were so much better working for ourselves. I had also talked with so many people who felt disconnected from what they did and hit this wall mid-career. But I think a lot of people are afraid to change paths: I’ve got kids and credit cards — How do I make a big change at that point? I think it’s scary and that’s what stops a lot of people.

WSJ: How did you conduct research for your book and find the right people to interview?
Ms. Remling: I did a lot of research using Google and referrals to find the people. I was trying to find people who’d left a corporate job to start a company or were trying to innovate inside their own company. My husband around the same time wanted an Airstream trailer just for us to enjoy weekends. I came up with the idea of traveling around the country to interview people in person and pitched the idea to the president of Airstream, and he gave us a $70,000 silver travel trailer. We lived and worked in that and traveled about 5,000 miles in summer of 2007, interviewing about 40 people.

WSJ: What are some of the things you discovered through these interviews?
Ms. Remling: One common theme in the interviews was it usually takes longer than you think to figure out your calling and start a business. Most entrepreneurs are optimistic by nature or they wouldn’t get into business for themselves. But it really requires some deep clarity about what you’re doing and that’s time-consuming. Another thing is the importance of finding others to help. A lot of people feel that they need to be an expert at everything and do everything themselves. But the most successful people find other people to help them achieve their goals. Many we interviewed said they waited too long to hire somebody. Another common issue we ran into was the challenges of getting out of the corporate mind-set and realizing you don’t necessarily need to handle everything as you did before. For example, when I started my consulting business I would get up and work a normal workday. But I started to realize that wasn’t the best schedule for me. I now get a lot of work done in the mornings and then go exercise in the late afternoon and return to work in the early evening. Creating boundaries between work and home life is also a big hurdle for new entrepreneurs. You have to have a separate workspace and step away from it and take time to do other things or it can get really wearing.

WSJ: Given what you’ve learned through your book research and your own experiences, what advice would give to people thinking about leaving a corporate job to start a business now?
Ms. Remling: I think it’s important to have your own network of people who can help you and advise you. If you have a clear picture of what you’re trying to do, many people are happy to help you without charging a huge consulting fee. Even just use sites like LinkedIn and build a network of people in your field and reach out to them. Also, have a clear picture of what you’re trying to do. Take some time to ask yourself deep questions and create a vision statement. It’s about asking yourself some of the bigger questions in life and then defining what your business is going to look like. What will the office look like? What will your clients look like? How will you be spending your time?

Readers, do you relate with the challenges Ms. Remling describes? Any advice for aspiring entrepreneurs today?