Quick Japanese Guide

Here's a quick and easy guide on the name attachments.
-chan - This is an intimate form of address. Close families use it and close friends use it. It's used for little children. You NEVER call anyone older than you '-chan'. Most people stop calling each other -chan after the age of 14 or so.
-san - The usual term for respect. It can mean Mr. or Ms. It is used for strangers and people you don't know well who are more or less in the same social status.
-sama - A very respectful ending used for Gods, Kings, your boss, etc.
-kun - Usaed by socially superior males to socially inferior ones (guys in a higher grade to a lower grade.) It is also used around male students and boys who grew up together.

Now that you've gotten all of that, here are some commonly said words and phrases in the series.
Abunai! - Watch out!/Duck!
Ai shiteru - I love you (Note: this is an EXTREME form of love. VERY VERY emotional. Saying I love you is USUALLY done with "suki da yo")
Arigatou (Gozaimasu) - Thank you
Baka! - Stupid/Silly
Chotto Matte - Wait
Daijoubu ka? - Are you alright?
Daisuki! - I REALLY like you! (I REALLY love you!)
Doushite? - Why?
Ganbatte! - Good luck!
Ginzuishou - Silver Crystal {for all you Sailor Moon Fans}
Gomen (Nasai) - I'm sorry
Hayaku - Hurry!
Iie - No
Ikimashou! - Let's go!
Itai - Ouch
Iya - No (to an action)
Kakkoii! - Looking Good!
Kawaii - Cute
Kirei - Beautiful
Kite Kite! - Guess what!
Komban wa - Good Evening
Konnichi wa - Good Day/Hello
Masaka! - No way!/I can't believe it!
Moshi Moshi - Hello [on the phone]
Nani? - What?
Nigero! - Run!
Ohaiyo Gozaimasu - Good Morning
Onegai/Onegaishimasu - Please
Oyasumi Nasai - Good Night
Shi ne! - Die!
Sonna! - It can't be!/No way!
Sou ka - I see..
Sugoi! - Awesome!
Suki da yo! - (I like you, literally) I love you
Suteki! - Cool!
Yamete! - Stop it!
Yokatta - I'm glad
Yoshi! - Alright!
Youma - Monster
Yurusan/Yurusenai - I will not forgive you

Bad words. They're just really useful whenever you feel the need to curse, but not get caught ;P~ And I just think they're funny.
Quick note, most of these words are one word phrases--they can mean different things depending on the context. Just because I have it written: "You Freak!" doesn't mean it won't mean "She's a freak" etc.

Baishunfu - That girl's a slut!
Busu - Ugly (from the word for pig) Just about the WORST thing you can call a girl.
Chikuso - Damn, Kinda like if you said, "DAMN! I dropped a dollar down that storm drain on accident!" (silent i and u)
Gaki! - Brat!
Haibokusha - You Loser!
Henshu - Freak!
Hentai! - Pervert/Freak!
Kimochi warui - Nasty!
Manuki - Dumbass
Misuborashi - Sleeze!
Mitame Hen! - You look stupid.
Mokatsuku - I'm Really Pissed Off
Okama - Fag
Omanko - Pussy
Oshikko - Piss