Some excellent language sites
Here are some websites I use regularly for japanese.
You can enter English or Japanese words
This one is the best. It even offers examples of how to use the words in sentences and often uses common sayings or phrases as the examples. Problem is, you need to know Hiragana to use it.
http://www.saiga-jp.com/kanji_dictionary.html
This is another good website. You don't need to know hiragana to use it.
http://linear.mv.com/cgi-bin/j-e/dict
And of course, google translate.
However, I would highly recommend that if you want to study some japanese that the very first thing you do is learn the ~80 hiragana characters. Forget Katakana for now.
Study this chart:
http://blog.asiahotels.com/wp-conten...e-alphabet.gif
You can use the chart to help use the first dictionay I mentioned.