This is a collection of weird facts about Sailormoon you may not have known before.  It's just a buncha random information that I couldn't fit in anywhere else...
Tau Ceti, where the villains from SMS come from, is actually a real place.
In Japan, the entrance exams to get into high school are very competitive, and they really do go to cram schools (juku) like Ami does.
Sailor TinNyanko's civilian name in the manga was Suzu Nyanko, suzu means bell, and she wore a bell around her neck.  The "nyan" in her name is Japanese for the noise a cat makes.
In the anime, Michiru could paint (and one of her paintings, "Space", was in a museum) but she didn't in the manga.
Midorikawa Hikaru played Ail in SMR and Fiore in the R movie, and Touma Yumi played both Ann and the Kisenian Flower from the movie.
Ikuhara Kunihiko, who directed Sailormoon R and S, also directed Shoujo Kakumei Utena, and the same animators worked on both series.
Rei's religion, Shinto, is a real religion that most people in Japan practice (they're either Shinto or Buddhist, mostly).
Midorikawa Hikaru played Tamahome in Fushigi Yuugi, and Touma Yumi played Yui, and Araki Kae (Chibiusa) played Miaka.  In Slayers, Midorikawa played Zelgadis and Touma played Shilfiel (six degrees of separation?)
The Starlights were female in the manga (as opposed to being males who turned into females in the anime), and even though Seiya was a woman in the manga she still had a crush on Usagi.
Ironmouse's civilian name, Chuuko Nezu, is a pun.  Chuu means mouse, and nezumi means rat. 
Leadcrow's name is a pun too (Karasuma Akane).  Karasu from her surname means crow, and the "aka" part from her given name means red (and she has red hair, and Leadcrow is pronounced Redcrow in Japanese).  Kane (from her given name) means metal too.
Rei writes her name with katakana, which is the Japanese writing system usually reserved for foreign words.  Some Japanese teenagers do this because it's easier to write.  To be grammatically correct though, it would be written in hiragana, the simplified alphabet used for most girls' names.
In the manga the senshi have their own castles: Mercury's is Mariner, Mars's is Phobos Deimos, Venus's is Magellan, Jupiter's is Io, Uranus's is Miranda, Neptune's is Triton, Pluto's is Charon, and Saturn's is Titan.  These are named after the planet's moons, except for Mercury and Venus which have no moons, in this case they were named after space probes.
The reason they wear sailor suits is because sailor suits are symbolic of a rite of passage for girls in Japan.  Most Japanese school uniforms are styled like sailor suits.
The English teaching system in Japan is considered to be one of the worst foreign language teaching systems in the world.  Still, lots of Japanese people like saying English words because it's "fashionable" or whatever, and this is why lots of things in Sailormoon are in English.
There's a Japanese legend about a rabbit on the moon who makes mochi (rice cakes) and this is where Usagi's name comes from (Tsukino Usagi means rabbit on the moon).  Luna's password for the arcade thing is "The rabbit on the moon pounds the mochi".  This is a running joke through the series, and it explains Usagi's hairstyle and why she doesn't like carrots.
Pluto is actually the god of death and Saturn is the god of time, but the senshi roles were reversed for an odd reason..
Haruka and Michiru have rings in the manga, but they aren't wedding rings, they're promise rings that symbolize their promise to take care of Hotaru.
A running joke in the series is that Usagi can't write kanji, she can only write hiragana (simplified versions of the kanji)
In the manga, Ami said that her ideal man would be Albert Einstein (whom she calls Einstein-sama)