Art:
http://scrapcoloring.com/
http://scratch.mit.edu/
Chess:
http://www.chesskid.com
For Parents:
http://www.commonsensemedia.org
http://www.commonsensemedia.org/website-reviews/all-ages/educational?action=new-releases
Kid News:
http://magazines.scholastic.com/
Mandarin:
http://www.omniglot.com/
www.multilingualliving.com
Get Talking Chinese
The First 100 Chinese Characters: Simplified Character Edition
http://www.semanda.com/wordlists_select.aspx?activityID=11
http://www.betterchinese.com/Home.html
General language tools:
http://www.chinese-tools.com/
http://www.mandarintools.com/
http://zhongwen.com/
http://www.learnchineseeveryday.com/
http://www.chineselearner.com/
http://www.clearchinese.com/learn-chinese
http://www.minmm.com/
http://www.chinasprout.com/
Pinyin and Tone:
Seattle Public Library books with pin yin
http://pinyin.info/
http://pinyin.quickmandarin.com/
Characters:
http://www.semanda.com/
http://www.skritter.com/
Reading:
http://www.echineselearning.com/
Dictionary:
http://www.mdbg.net/chindict/chindict.php
http://www.purpleculture.net/chinese-english-dictionary/
Chinese Culture:
http://depts.washington.edu/chinaciv/
http://www.cultural-china.com/
Math:
https://www.everydaymathonline.com/student_login.html
http://www.mathplayground.com
http://www.mathsisfun.com/
https://www.xtramath.org/home
www.khanacademy.org
www.mathplayground.com
www.dreambox.com
A Mobile Math List
Programming and Puzzles:
http://www.csunplugged.org/
http://www.starfall.com
Tumblebooks (free via Seattle Public Library)
Science:
http://www.nap.edu/
http://www.exploratorium.edu/science_explorer/
http://www.billnye.com/for-kids-teachers/
http://science.howstuffworks.com/
http://www.hhmi.org/coolscience/
http://www.extremescience.net/ (look out for the volume!)
http://coolcosmos.ipac.caltech.edu/
https://student.societyforscience.org/sciencenews-students
http://www.fs.fed.us/gpnf/volcanocams/msh/
Spanish:
http://www.elhuevodechocolate.com/
http://www.lapl.org/kidspath/sites/espanol.html
Miscellaneous Subjects:
SPS Library Services Online Student Resources
http://www.worldbookonline.com/training/kids/html/kids_1.htm
http://old.seattletimes.com/html/businesstechnology/2017479540_ptteentween11.html