This manual provides a comprehensive framework for the systematic study of insects, with emphasis on their collection, preservation, morphology, and classification. It outlines standardized methods for collecting insects, including immature stages, and details the equipment and techniques essential for effective preservation and mounting of specimens. The external morphology of insects is presented in a structured manner, focusing on the head, thorax, and abdomen as key anatomical regions. Further, specialized structures such as mouthparts, antennae, legs, wings, venation patterns, and wing coupling apparatus are examined to illustrate their diversity and functional adaptations. This manual provides a holistic introduction to insect biology through the study of external morphology, internal anatomy, developmental stages, and classification. It emphasizes dissection-based understanding of digestive and reproductive systems, examines larval and pupal forms to explain life cycles, and outlines diagnostic features of major insect orders such as Orthoptera, Dictyoptera, Odonata, Neuroptera, Isoptera, Thysanoptera, Coleoptera, Diptera, Hemiptera, Lepidoptera, and Hymenoptera. Designed to combine theory with practical skills, it establishes a strong foundation for advanced entomological research and applications.