Water Heating Infographic
Visual Water Heater Guide

Here is an interesting info (infographic) about water heating - in short, taken from the energy.gov website, called Energy Saver 101.

It nicely lays out what you need to know about residential, potable water heating, how to choose a water heater and what to consider, different types of water heaters with pros and cons and fuel type, about the maintenance, how to save energy and money with tax credits and rebates tips.