This study seeks to understand the information-to-knowledge experience of English Language Learner (ELL) students in a Guided Inquiry project undertaken by the school librarian and subject teachers. As a pilot study, it provides an in-depth examination of two Korean 11th grade students in a biology class of a high school in New Jersey. During the project, data were collected through questionnaire, surveys, search journal, search sessions, observation, students' papers, and semi-structured interviews. The findings of this study will contribute to understanding of how ELL students experience information search and knowledge building through a complex research project in English so that school environments, including school libraries, can provide meaningful instructional and service interventions for them.