||Prior research and best teaching practices in L2 academic writing suggest that a combination of information literacy content and language teaching is effective in helping L2 writers learn the skills needed to become effective researchers (Bordonaro, 2011; Grabe & Stoller, 1997; Stoller, 2004). Research has also shown that student and instructor beliefs about learning influence the impact of curricula (Brown, Murphy, & Nanny, 2003; Jackson, 2005; Maybee, 2006; Ouellette, 2011). Using a mixed methods approach, this study examines L2 writer and instructor perceptions of the effectiveness of the L2 Writer Subject Guide, a curriculum integrated library guide, in developing skills in using the library for research purposes. Student perceptions were analyzed via pre- and posttests, surveys, and focus group data using qualitative and quantitative instruments. Effectiveness of the L2 Writer Subject Guide was also analyzed in the context of student performance on module assessments. Quantitatively, there was no significant difference in the scores for the pretest and the posttest. Qualitative results among the four instruments reveal that students have diverse perceptions of the L2 Writers Subject Guide's effectiveness and also variable user experiences. Findings also suggest that the L2 Writers Subject Guide builds resource awareness among students, but the purposes of these resources are still misconstrued. Similarly, students reveal much declarative knowledge about the research process but have not yet developed the procedural knowledge to effectively use research resources and processes to incorporate sources into their own work. Data show that the L2 Writers Subject Guide complemented current instruction in one ESL writing class and provided diverse teaching and learning opportunities.