First-generation college (FGC) students have been described as an underrepresented group in comparison to their continuing-generation counterparts (non-FGC students). Studying college students' socialization experiences and their use of academic resources can help us understand how to facilitate their academic success. Incorporating Sonnenwald's "information horizons" ("IH"), Astin's "Input-Environment-Outcome" ("I-E-O") model, and Weidman's model of "undergraduate socialization", this study examines FGC and non-FGC students' socialization experiences in relation to their information behavior. The theoretical framework of "IH" describes how contexts, situations, and social networks shape individuals' information behavior; this framework emphasizes the role of social networks in information-seeking activities and the relationships among sources used by individuals. "I-E-O" and "undergraduate socialization" models emphasize the interaction aspect in undergraduate socialization. To delineate the complex networks in college students' information-seeking activities, this study investigates how students position various information sources on their academic IH maps and examines the sequential and referral relationships among sources. Specifically, the study focuses on the roles of peers, professors, and parents in IH. With an explanatory mixed-methods research design, this study investigates how students' backgrounds and college socialization experiences influence their IH. A survey was used to examine students' information behavior in academic situations. Using critical incident techniques, interviews and participants' IH map-drawings were also used to solicit students' personal accounts of their socialization and source use experiences. The study finds that frequently-used sources are typically placed in the preferred zones on the IH map, are consulted as one of the first steps, and possess a referral quality. The findings also demonstrate that students with different FGC status and in different class cohorts have different socialization experiences. Socializing agents, such as parents, peers, and professors, are important factors affecting students' academic source use behavior; information literacy courses positively affect students' use of the library and experts. The study reveals that socialization elements are an important aspect to be added to the framework of IH and helps advance the use of mixed-method approaches to study information behavior. Practical implications for the university and university library as well as research implications for theory and methodology are discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]