I want to introduce archchinese.com is because this is a very useful site for students to learn or to search for the Chinese characters or phrases easily
http://www.archchinese.com/
I have been introducing this site to my Mandarin Chinese students, and the students love to utilize this online Chinese-English dictionary as s tool not only give them the defination of a Chinese character, but also teach them how to read by clicking the sound button.
It also shows the radicals in a character, and the writing stroke orders are showed in animated way. The stroke orders can also dismentaled into stroke by stoke order.
I strongly recommend Mandarin teacher or whoelse are interested in learning Chinese use this site.