Equipment Sizing Tools

Here are some links which contain calculators which can be used to size equipment such as motors, cables, batteries, etc

http://www.openelectrical.org 
Excellent website containing tools for calculating sizes of batteries, cables and other equipment. Site also contains Technical Guides and Reference Data

http://www.engineeringtoolbox.com/electrical-motor-calculator-d_832.html 
Online Electric Motor Calculator

http://www.kilowatts.com.au/calculator-voltage-drop.php 
Voltage Drop and Cable Size Calculator for ELV Solar Power Systems

http://www.kilowatts.com.au/wire-size-conversion-table.php 
Wire Gauge Size Conversions AWG to Metric - Diameter and Cross Sectional Area

http://www.kilowatts.com.au/energy-audit.php
Typical Power Consumption Values for domestic appliances

http://www.cable-calculations.co.uk/simplecalculator 
Online tool for cable and circuit breaker calculation (LV)

http://users.telenet.be/worldstandards/electricity.htm
Details of Voltage and Frequency used in different countries around the world.  Contains details on plugs and sockets in each country