The Honest Life will offer readers tips on how to create a healthier life, the actress told People.
The book is expected to focus on Alba's career and life as a mother, as well as tips on recipes, interior design, and homemade beauty treatments.
Alba, who described news of her first book as "totally crazy but amazing", explained that the project is aimed at people "who are in the middle but want to create a healthier life".
"It will be easy and fun and I want it to be really colourful," she said. "Everything in this book will be something meaningful that I've incorporated into our lives. I wanted some kind of handbook with all the information I was consuming so I could apply it in a practical way."
Alba recently revealed that she tries to protect her 3-year-old daughter Honor Marie by pretending that everyone is followed by the paparazzi.
The Honest Life is due to be published in 2013.