Lewis Structure

The Lewis structure is a representation of chemical bonds and elements based on its valence electrons. Many of theses diagrams are used to help diagnosis the electron geometry of the covalent bond. Any easy way to do these structure is count all the the electrons in the atom, place least electronegative element in the center, and place electrons throughout the bonds.

 
Octet Rule

http://socratic.org/questions/how-many-valence-electrons-are-in-bromine
Co2 Dot structure Video