I'm gonna do a post about Japanese, just cause I've been collecting mental short cuts for a while now. I may expand upon this. So here is some general info and musings to get you started.
Japanese has no plurals of a proper sort. Sometimes a word is made plural by repeating it (though the first syllable of the repeated word often changes, ex:ひとびと) sometimes one can indicate a group exists with a postfix.
There is no future tense to worry about. Just context.
Japanese sounds come in little beats called moras, one mora for each kana usually. This makes haikus a breeze in Japanese. Sometimes they add onomatopoeic emphasis by lengthening a mora noticeably.
は and が Seem related but they are not. は is for topics and specificity. が is for "subjects" (fishy terminolgy, but what can you do) and introducing new information.
へ is usually "towards". In the same manner に is often "to". で is likely "at" or "by means of" .で differs from に in that it indicates a location at which action takes place (mnemonic: "I did it at de place").
I-adjectives can conjugate like verbs, cause they secretly are verbs. Verbs in their tai and nai forms become essentially adjectives (i-adjectives). So あそこに行きたい means "I want to go there" in Japanese and English, but also sort of means, "there is a want-to-go-type of place" in Japanese. This sort of thing is an weird difference between the two languages.
Also, when describing feelings and the like (in the sense of "this makes me happy") it is usually i-adjectives that seem to be used, as opposed to how English speakers personalize their feelings, making the speaker the subject. Essentially you say "this is a happy ～" instead.
All you need for a correct Japanese sentence is a verb. The verb always comes last, and everything before it can be in any order as long as all words are still attached to their particles.
The copula (read: linguistic equal sign) is also a verb Japanese, and it conjugates like one (with some irregularity), and can function like one at the end of a sentence. It's a word that indicates existence. です is "=".
ある and いる are used for existence. Verbs don't need copulas behind them (compare to English: "I run"), which is why a verb alone is a complete sentence.
The masu form is already polite and a verb, so it doesn't need desu to the point where desu isn't even used in masu using sentences--excepting the past negative (ありませんでした which is a caveat necessitated by masu not having a negative past tense cogitation).
I-adjectives don't need copulas (because they are verbs) but you can add です behind them to be polite. Copulas are often tacked on to add politeness (in these situations they have no grammatical function). だ is not polite, so it doesn't get attached to i-adjectives. If you add でございます、you have to conjugate the i-adjective a little (as in おはようございます).
If you wanna sound pissed, ad な to the end of a dictionary form of a verb (this means ”don't do that verb!").
Men use ぜ and ぞ instead of よ, while women use わ before よ. This wa and the honorific o are actually elegant, beautifying speech, and for some reason they are considered polite, and mainly used by women. Men can use わ, if they are really rich princes, or speaking kansai-ben.
Japanese people learn their own language in very different terms and have a hard time explaining it to foreigners. Perhaps this is why they think their language is the hardest on earth. But in actuality, Japanese is a very simple language. Learn verb and adjective conjugation, especially the te form and you are in for smooth sailing. Consult with the marked language resources linked on the right menu bar of this blog for more info and elucidation; I especially recommend Tae Kim's guide. I also recommend downloading Firefox and adding the Rikaichan plugin. Also, get a nintendo DS and buy 漢字そのまま.
I edit this post from time to time --Jan 23rd, 2009