What goes through your mind when you prepare lessons? What do you take into account when designing a learning environment? What do you take into account during your teaching experience when designing learning environments? This book deals with some issues related to teacher planning such as mental images in the educational context, intentionality and the influence of the teacher's thinking on the students' reality. It tries to integrate concepts from psychology and pedagogy to contribute to the understanding of teachers' thinking. It is therefore assumed that lesson planning is an act that is carried out by most teachers, and for this reason it is important to contribute to its analysis in order to achieve improvements in educational processes.