Note. Unity 5 introduced the Standard Shader which replaces these shadersA program that runs on the GPU. More info See in Glossary.
The Transparent Cutout shaders are used for objects that have fully opaque and fully transparent parts (no partial transparency). Things like chain fences, trees, grass, etc.
One Base texture with alpha channel for Transparency Map
One Normal mapA type of Bump Map texture that allows you to add surface detail such as bumps, grooves, and scratches to a model which catch the light as if they are represented by real geometry. See in Glossary normal map, no alpha channel required