As Alexis Ohanian learned when he helped to co-found the immensely popular reddit.com, the internet is the most powerful and democratic tool for disseminating information in human history. And when that power is harnessed to create new communities, technologies, businesses or charities, the results can be absolutely stunning.

In this book, Alexis will share his ideas, tips and even his own doodles about harnessing the power of the web for good, and along the way, he will share his philosophy with young entrepreneurs all over...