Vocabulary
What you should know
Otaku- Anime Enthusiast/fan (means you in the very formal sense) in Japan it means essentially the same as nerd.
Anime- Japanese Animation
Subbed/Dubbed- Subtitled- Japanese language with subtitles/ english dubbed
Fansub- A fan made subbed copy of an anime, true they are breaking Copyright laws.
Manga- Japanese comics, most anime are based on them.
Hentai/Ecchi- Strange or Perverted, Adults-Only Anime.
Mecha- Anyting that's a Machine in Anime(Gundams, for example)
Shojo- Girls Style anime or Manga
Shounen- boys style anime or Manga
Seiyuu- Voice actor/actress
Japanese Words Commonly used by Otaku-
Kawaii- Cute/Cool
sugoi- Cool
Chibi- mini or superdeformed character- common in Shojo anime/manga.
Konnichiwa- Hello In Japanese
Arigato- Thank you
Konbanwa- Good Evening
Baka/Bakka- Stupid, idiot, any other basic insult.
Domo- very much
Name suffixes-
~san- indicates a neutral distance. You would tend to use this if you just met the person; also if you are not very intimate with the person speaking to.
~sama- indicates that you hold the one spoken about in high esteem. In many shoujo animes, girls tend to use it to indicate that they have a crush on the person being spoken about.
~chan- used towards a child (especially a female one). It is also used amongst younger children and schoolmates. If you use this, you are familiar with the subject and probably have some affection for them.
~kun- very similar to "~chan." But, whereas "~chan" is used more commonly towards girls, "~kun" is more commonly used towards boys. (Of course there's always the tomboyish type of girl who likes being refered to as "~kun")
~sensei- the word "Sensei" literally means "teacher, master, instructor, physician, etc." You use "~sensei" to address someone in a respected occupation, such as these.
~sempai- used towards someone you have a high regard for. "~sempai" tends to be used towards upperclassmen, superiors, and older people. If you use it towards someone, it usually indicates that you have respect for them.