As classroom teachers, it is essential that we become conversant with the type of instructional materials, which can be used in any teaching/ learning situations. Instructional materials as it is said are synonymous with what we call ‘teaching aids’ here in Nigeria. Instructional materials constitute alternative channels of communication, which a teacher can use to convey more vividly instructional information to learners. They represent a range of materials which can be used to ‘extend the range of vicarious experience’ of learners in a teaching-learning situation. Recently, in Nigeria, Educationists have realized the importance of these instructional materials for effective classroom teaching. Hence in 1945 and in 1985, the federal ministry of Education organized an exhibition of improvised materials by instructional developers all over the federation. A major aim of these exhibitions was to identify materials, which teachers have improvised as preclude hopefully, to their further refinement through the process of formative evaluation. Though a center for educational technology has sprung up in colleges of education and universities all over the country, it is doubtful if practicing teachers in Nigeria are aware of procedures for selecting appropriate instructional materials. This paper however, presents an overview of the relevance of instructional materials in our school system and thus recommended among others that the use of several kinds of instructional materials to explain one particular concept must also take cognizance of individual differences among the learners. Meaning/definition of instructional materials: Instructional materials refer to those alternative channels of communication, which a classroom teacher can use to concretize a concept during teaching and learning process. Traditionally, classroom teachers have relied heavily on the ‘talk-chalk’ method during their teaching. But recently, instructional materials help to provide variations in the ways in which messages are sent across. In using instructional materials teachers and students do not only extend the range of sense organs we use but also extend the range of materials used for convening the same message through the same organ. For instance, in teaching a topic a teacher can manipulate real objects or use their stimulators. Instructional materials therefore constitute the media of exchange through which a message transaction is facilitated between a source and a receiver. In addition to extending the range of materials that can be used to convey the same instructional message to learners instructional materials also facilitate the ‘process’ nature of communication. In this passage, the process nature of communication implies that both the source and the receiver of a message are actively involved in a communication encounter. Infarct, it means that both the receiver and the source share and exchange ideas, feelings in any communication (Tyler, 1987, Dike 1989)