Also, this is a good Jaapnese/English online dictionary.
Its all in japanese, but don't get confused! You type words in English/Japanese(no ro-maji) in the blank below
"英辞朗 on the web", and click on "英和・和英" and you will find many examples. The best part of this dictionary is that it has a loooot of examples, and thats how you learn languages :)
Example: i tyled in "暑い"(ATSUI(=hot)--if you just type it in hiragana, it wont come up with many examples..)
There are some interesting/informal/usuful expressions.
外はめっちゃ暑い。
-->It's mad hot outside.
今日はうだるように暑い。
-->It's a boiling hot day.
あー暑い!暑いっていうとよけい暑いけど暑いものは暑い!
-->Oh, it's so hot. I realize that saying "it's hot" makes me feel hot, but really is hot!