Typically, a Reference Book is one that cannot be removed form the library, but since we're working online and this page is all about open and free sources of information you can get these whenever you'd like:
* Merriam-Webster Dictionary
* Dictionary.com- pulls information from various dictionaries.
* Rhyming Dictionary- useful for writing poetry and annoying your friends.
* Bartleby's list of quotations- searchable by chronology, keyword and author
* Brainy Quotes- searchable by keyword, type and author
Almanacs (usually an annual publication of interesting facts, but online resources tend to be updated a little more frequently):
* Encyclopedia Britannica- Go to the Electronic Database and access this through the Electronic Library of MN (you won't need an account)
* Wikipedia- This often gets a bad rap because anyone can edit it, but there are certain safeguards in effect. One study has also shown that experts find it more more reliable than non-experts. Britannica claims the two are equal in reliability. At any rate, use it as a guide. You can always track the resources back in the works cited at the bottom of each wiki page.