Here are good K12 websites about word (and phrase) origins (especially the * ones):
(compiled by Lesley Farmer)
IPL guide to word and phrase origins http://www.ipl.org/div/pf/entry/48468
LibrarySpot Etymology Dictionaries http://www.libraryspot.com/dictionaries/etymologydictionaries.htm
Language sites http://www.verbivore.com/rllink.htm
Evolution of Human Languages (check out interactive maps) http://ehl.santafe.edu/intro1.htm
* Evolution of languages http://www.exploratorium.edu/exploring/language/
History of English http://www.ruf.rice.edu/~kemmer/Words04/history/
English-Word Info (includes quizzes) http://wordinfo.info/
World Wide Words (International English with a British viewpoint) http://www.worldwidewords.org/
* Visual graphical dictionary http://www.visuwords.com/
* Word Origins (Fun with Words) http://www.fun-with-words.com/etymology.html
Word Origins http://www.worldwidewords.org/
* Etymologic (the toughest word game on the Web) http://www.etymologic.com/
* Origin of Words and Names (by language and topic) http://www.krysstal.com/wordname.html
Indo-European Etymology Dictionary http://www.indo-european.nl/
French website on etymology (includes European languages) http://www.lexilogos.com/etymologie.htm
Phrase Finder http://www.phrases.org.uk/index.html
Etymologically Speaking http://www.westegg.com/etymology/
Phrase Finder http://www.phrases.org.uk/index.html
Expressions and Sayings http://users.tinyonline.co.uk/gswithenbank/sayindex.htm
Double-tongued English (fringe and new words) http://www.doubletongued.org/
Way with Words http://www.waywordradio.org/
Behind the Name http://www.behindthename.com/
Name Meanings http://www.name-meanings.com/index.php
Baby Name Wizard http://www.babynamewizard.com/namevoyager.html/lnv0105.html
Baby Name Worlds (has pregnancy info) http://babynamesworld.parentsconnect.com/
Behind the SurName http://surnames.behindthename.com/
Last Name Meanings http://www.last-names.net/
Internet Surname Database http://www.surnamedb.com/
* Soda vs Pop http://popvssoda.com/
* Etymology’s View if the World http://www.spiegel.de/fotostrecke/fotostrecke-37310.html
* Native Names map http://ngm.nationalgeographic.com/2009/04/departments/native-names-interactive
* Atlas of True Names http://www.kalimedia.com/Atlas_of_True_Names.html
Country Name Etymologies http://en.wikipedia.org/wiki/List_of_country_name_etymologies
Country name etymologies http://www.fact-index.com/l/li/list_of_country_name_etymologies.html
* Spice Pages http://www.uni-graz.at/~katzer/engl/
* Periodic Table in different languages http://www.vanderkrogt.net/elements/multidict.php
Spanish etymology http://etimologias.dechile.net/
Spanish idioms http://www.elcastellano.org/palabra.php
Italian etymology http://www.etimo.it/
French etymology http://www.cnrtl.fr/etymologie/
Dutch etymology http://www.etymologie.nl/
Swedish etymology http://runeberg.org/svetym/index.htm
German etymology http://www.koeblergerhard.de/derwbhin.html
German website on etymology http://www.etymologie.info/~e/
Russian etymology http://etymolog.ruslang.ru/
Indo-European Etymological Dictionary http://www.indo-european.nl/%5Cindex2.html
Chinese Character Etymology http://www.yellowbridge.com/chinese/character-etymology.php?searchChinese=1&zi=%E5%9C%8B
Kanji Network http://www.kanjinetworks.com/
* Chinese Etymology: Color http://www.colourlovers.com/blog/2008/03/07/the-colors-of-language-chinese-etymologies/
Several etymological dictionaries (unusual languages) http://www.freeweb.hu/etymological/
* Language Construction Kit http://www.zompist.com/kit.html