Formal charges act as a signpost to indicate which atoms are sharing (or not) their electrons in an unusual manner in a Lewis structure. They give more insight into electron distribution and hence reactivity and physical properties.

A brief introduction to organic nomenclature. A bit longer than I hoped as I added some examples (pluses and minuses I guess).

How to draw and interpret skeletal or line diagrams

A brief summary of common functional groups

An overview of hybrid atomic orbitals and how they are applied to valence bond theory.

A quick introduction to thin layer chromatography - hopefully useful for first year labs.

A short description of Lewis structures