I often use the rikaichan plugin if I need to look up a Kanji. While this is usually sufficient, there are times when I need some more context to be able to understand how the Kanji is used. That’s when alc.co.jp really comes in handy.
The meaning of many words becomes much clearer because they are shown in practical phrases one would hear in everyday conversation in Japan. For example, the word “生活” alone seems to have several thousand example phrases listed. Many are taken from real articles, like those from the Hiragana Times.
Definitely a page worth bookmarking!