Mabel Armstrong, bought her first two fixer-upper duplexes in 1987 - on her credit card.

For the next few years Armstrong taught herself the investment skills she needed: learning about her local real estate market and its cycles, evaluating properties financially and physically, and producing effective loan packages. In addition, she learned to rehabilitate distressed properties, developing skills in painting, sheetrock installation, electrical work and plumbing.

Starting with little cash and no experience, Armstrong built a rental property portfolio approaching $2 million.

"I think small rentals are the best kept secret in the investment world," said Armstrong. "You can get into this investment with little or no cash. It pays off better than anything else, and your renters actually buy the investment for you."

Once she figured this out, and realized that most people don’t know it, she knew she had to get the word out. So she wrote How to Invest in Rental Properties Without Mortgaging Your Soul.

Armstrong’s second reason for writing a book is her conviction that rental owners have a big impact on their communities. Enlightened owners can provide decent, affordable homes and still make money. "You can do good as you are doing well," she said, She wants to promote the idea that we can make a good living at the same time that we are being good citizens.