What does it take to consider a planet potentially habitable? If a planet is suitable for life, could life be present? Is life on other planets inevitable? The Search for Habitable Worlds answers these questions and provides both the general public and astronomy enthusiasts with a richly-illustrated discussion of the most current knowledge regarding the search for extrasolar planets. Nearly everyone wants to know if we are alone in the universe. This book might not have the answers, but shows where we should look. The Search for Habitable Worlds is a fun and accessible book for everyone from middle schoolers to amateur astronomers of all ages. The use of non-technical language and abundant illustrations make this a quick-read to inform everyone about the latest movement in the search for other planets we might be able to inhabit. After a brief discussion on why humans are hard-wired to be curious and to explore the unknown, the book describes what extrasolar planets are, how to detect them, and how to pin down potential targets. In addition, a data-driven list of the best candidates for habitability is profiled and the next generation of exoplanet-hunting scientific instruments and probes are identified.