Described here is a study of how students actively read electronic journal papers to prepare for classroom discussions. Eighteen students enrolled in a graduate course participated in this study; half of them read the documents privately, while the other half shared their readings. These readers were digitally monitored as they read, annotated, and shared the electronic (e-) documents over a course of several weeks during a semester. This monitoring yielded a comprehensive data bank of 60 e-documents (with 1923 markings), and 56 computer logs. Using semi-structured interviews, the reading, marking, and navigational activities of the participating readers were analyzed in detail. Under scrutiny were a range of activities that the subjects carried out. Analyses of the data revealed the types of markings that the users employ, and the ways in which those marking were placed. A derivation of the user-perceived functions of the marking structures was then carried out. The findings then lead to several implications for informing the design of reading and marking applications in digital libraries.