References

General Reference Portals

refdesk - Great place to find all types of reference materials ,and other information.

InfoPlease - Excellent site for references especially encyclopedias.

Library Spot - very good site for references and other resources such as top books.

Dictionaries

Merriam-webster - Very good site that includes thesauras and Spanish/English.

YourDictionary - Very easy to use with lots of resources.

Dictionary.com - Very simple and easy to use.

Encyclopedias

Encyclopedia.com - great site and very easy to use.

Wolfram Mathworld - Excellent Math Encyclopedia.

Eh Net - Economic and Business encyclopedia.

Science Encyclopedia - very good science encyclopedia.

Almanacs

CIA World Factbook - most up to date and complete almanac.

50 States - Good for studying the U.S. states.

Atlas

World Atlas - Good for studying the world.

National Atlas - Very specific maps available on the site.

University of Texas Map Collection - Most complete online map collection available.

Conversion & Special

Online Conversion - Convert all kinds of measurements.

XE - Currency Converter

Quoteland - Quotes on every major subject.

On This Day - Find out what major events happend on each day of the year.