This qualitative inquiry studies the key factors influencing the process of building, growing, and sustaining a health information network among new mothers on Facebook, who live in Appalachian Tennessee. Grounded theory analysis of in-depth phone interviews reveal that (i) realizing information needs, (ii) turning to the Internet and social media, (iii) joining the Facebook group, (iv) building a community of practice on the group, (v) information practices of users, and (vi) deriving benefits to meet the information needs, help them build the health information network.