You can find good teen games for girls to download on iPhone on appcrawlr.com/ios-apps/best-apps-teen-girls
stardoll
There really is no "best" teen rated game because everyone has their own opinions on what is a good or bad game. In one opinion, Super Smash Bros. Brawl for the Wii is the best teen rated game.
one is tom clancys end war(takes place in WWIII) medal of honor airborne(not the new one that new one is rated M)
TRON: Evolution for PS3 is rated T for Teen, and it's been getting some amazing reviews - Kris Abel of CTV even called it the best game of 2010! http://www.krisabel.ctv.ca/post/Review-Tron-Evolution.aspx
Second Life is best virtual world for teens.
There are a few online games to teach you how to use the stock market. A few examples are Virtual Stock Exchange, The Stock Market Game, and YD Bank virtual stock market game.
Virtual Teen
emochatroom.com
the sims 3 online its dont cost or download it came out today
Imvu.com
For something such as learning Spanish, if your teen is struggling it is best to have an actual tutor help her understand the language better rather than doing online tutoring, unless she learns best using online resources. If you have any friends who know the language well you could always have them tutor your teen.
You can find good teen games for girls to download on iPhone on appcrawlr.com/ios-apps/best-apps-teen-girls
life
games.student.com/ is the best place for high school and college aged kids to check on games and if they are good or not. There are a lot of articles and suggestions on which games are the best to buy or rent.
stardoll
It used to be on cartoon network but, as you may have known,they have cancelled it and the best way to watch them is online.