With the ultimate goal of shifting the consistent, downward trajectory of African American adolescents' academic and personal success in formal schooling, the purpose of this study was to shift persistently negative perceptions about their native language and literacy practices, African American English (AAE), by fostering teachers' awareness, knowledge, and appreciation for its linguistic vitality. A formative research and design approach was used to implement and explore the impact of a nine-week, teacher-centered, professional learning series (PLS) focused on sociolinguistically informed instruction for traditionally marginalized adolescent students. The guiding inquisition of this study was: In what ways might a sociolinguistically informed professional learning series impact the way teachers think about, plan for, and implement instruction for their African American adolescent students? To address the specific questions of this study, qualitative and quantifiable data were collected including: researcher journal/field notes, participants' written reflections, transcriptions of audio-recorded sessions, records of participants' responses, and pre- and post-surveys and questionnaires that measured knowledge, attitudes, and awareness of language and AAE. The exigency of this study, the design of the PLS, and the data analysis procedures were grounded in sociocultural, sociolinguistic, and critical theories about language (i.e., acquisition, development, and use), and about teaching and learning. Iterative data collection throughout the implementation of the PLS prompted adjustments and modifications in the areas "of logistics," "andragogy," "methods," "interpersonal relationships of stakeholders," "technology," and "ethics" to increase its effectiveness. These adjustments and modifications were primarily based on participants' interests, inquiries, and learning needs. Analysis of qualitative and quantifiable data revealed that the PLS had a positive impact--at varying levels--on teachers' awareness, knowledge, and attitudes about AAE, and on the planning and implementation of instruction for their students. At the start of the PLS, participants generally had little to no preexisting knowledge about AAE, had little to no pre- or in-service teacher training on AAE, and possessed neutral to positive attitudes about AAE. Deeper analysis of qualitative data revealed that "time," "critical introspection and reflection," and "discoursal struggle," within a psychologically safe context, are crucial elements in becoming critical sociolinguistically responsive teachers. The findings of this study substantiate the need for more multi-phase professional development sessions for in-service teachers in the area of language variation as it relates to ideology, inequity, and instructional practices so that they are equipped to actuate an upward spiral in the academic and personal success of students in school and within a wider context of an increasingly pluralistic society. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]