http://trading-volatility.com/Trading-Volatility.pdf by Colin Bennett

Implied vs Realized

Vol cone shows how realized is more volatile than implied

Vol as a Hedge

Decomposing long vol: A poor hedge even beyond it's expected overpricing

Term Structure

Term structure supply/demand

Looking at variance vs implied vol term structure

Comparing term structures

Relationship of skew and term structure

Skew

Reasons for skew

Measuring skew

Skew is steeper in nearer dated

4 skew regimes and their deltas

Skew trading