Summary of basic principles
1. Opposite charges attract.
2. Like charges repel.
3. The more stable, the less potential energy. Nature tends to favor low energy, stable things, like the way people's rooms tend to get messy over time, or the way water runs downhill.
4. Resonance = stability. The more resonance, the more stability.
5. Electrons, a dearth of electrons, an overabundance of electrons, or electron movement, is the basis of bond formation and determination of stability in organic chemistry.