In this action research study, I designed, taught, and analyzed results of a unit in my eighth grade English language arts classroom. The unit focused on supporting students' critical reading of online texts. My research questions were: (1) Within a focal unit, how did I support my students' critical reading of online sources? (2) Within a focal unit, how did my students learn to critically read texts they accessed online? Drawing on Freebody and Luke's (1990) four-resources model, I found that students most frequently engaged as text participants and text users in their reading of online texts. Like my students' talk and my unit design, my instructional talk also tended to move between supporting students as text participants and text users. Conclusions are of interest to other classroom teachers, especially those concerned with literacy teaching and learning. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]