speaking of comparisons, I was thinking of some words that seem similar but seem to have a slightly different meaning I was curious about...
手伝う 助ける 救う (てつだう たすける すくう)
The first is more "to assist" someone with something. That is, you and them are both doing it, while the second is more like "help" or "save" me. Where they take over and do it for you, or it can mean to save someone. I've never seen the third.
選ぶ/択ぶ 選択する (えらぶ せんたく)
使う 使用する 利用する (つかう しよう りよう)
働く 努める バイトする (はたらく つとめる)
Don't know the first two, but hataraku is to work regardless of work place, tsutomeru is not used when you're self employed, it means working
for someone and the third is usually not a full time job.
試験 テスト (しけん)
simple. shiken is an exam (usually something serious) while tesuto is more of an on the spot quiz or test. Nothing serious.
知らせ 警告 注意 (しらせ けいこく ちゅうい)
The first is more to inform or let someone know something (literally "cause to know") while the last is more of a warning or a "take particular attention to the fact that...". Dunno about the middle one.
禁止 厳禁 (きんし げんきん)
自分 自身 自分自身 自己 (じぶん じしん じこ)
事件 場合 (じけん ばあい)
these are just a couple that come to mind... any ones you can help clarify would be great

Sorry, but I can't really help on the rest :S