Internet Accuracy Project's commonly misspelled, confused and misused words is a helpful collection of some of the most commonly misspelled, confused and misused words.

Weights, Measurements and Equivalents

Celsius and Fahrenheit Wind Chill Charts

Heat Index Charts and Celsius Humidex Table

U.S. Precipitation, and Frost/Freeze Maps

Plant Hardiness Zones for the United States and Canada

U.S. Postage Rates and USPS state abbreviations

U.S. Mail, UPS, and FedEx Holidays

U.S. Presidents in chronological order with their respective Vice Presidents

Internet Domain Country Codes

2012 Calendar

Guide to Roman Numerals

U.S. Law Enforcement Abbreviations and Acronyms

U.S. Law Enforcement Task Force Acronyms

International Law Enforcement Abbreviations and Acronyms

World Almanac and Book of Facts errors points out erroneous data contained in various editions of the World Almanac and Book of Facts.