The objective of this dissertation was to enhance my understanding about the process of construction of lesson plans and understand how teacher-learners view planning. This is the result of an exploratory practice process performed with my own group of English Language Teaching Practice in the context of a Higher Education Institute during the first bimester of the second term in 2007. In order to achieve this aim, two Potentially Exploitable Pedagogic Activities (PEPAs) were developed: a discussion held on the first day of classes about the characteristics of English teachers in the new century (registered in OHTs) and the teacher-learners’ end-of-term written report, in which they narrated or described their personal understandings of how the lesson plan construction was developed. All the generated written data were gathered and analyzed. The perception that, in order to plan lessons, teacher-learners used their belief system, at a conscious or unconscious level, led me to the construction of this practitioner research work. Oriented by the principles of Exploratory Practice, I also based my analysis on studies on teacher and learner beliefs as well as on pre-professional teacher preparation. My dissertation aimed at deepening my understanding on the nature of planning and the quality of life in my English Language Teaching Practice classroom, seeking to fill a gap in the area of preprofessional English teacher preparation on account of the scarcity of theories that derive from teacher-research of professional practices in this field.