This two-part study examines the emerging understanding of the reading process among preservice teachers (PTs), enrolled in a teacher preparation course on diagnostic reading. The study focuses on the use of reading assessment tools to understand the process of reading, while using reading inventories for diagnostic as well as pedagogical purposes. PTs’ self-reflections support a developing insight into the reading process. Through the process of inquiry and self-reflections, PTs discovered critical issues related to literacy, namely, metacognition, prior knowledge, cultural factors, instructional implications, and content area reading. These findings have implications for the teaching of reading as inquiry-based instruction, enabling teacher candidates to build their understanding of the reading process through an emerging personal model.