I've been a Sailor Moon fan since 2000. I got into it with the "Lunarock" album, the second English soundtrack album. Yes, my introduction to this massive franchise was an album of songs for which I had no context. I simply saw it at Wal-Mart, thought "I vaguely remember reading about this 'Sailor Moon' thing on the Internet, and, hey, hot girls", and I bought it.
I also got the English dub of the first movie on VHS at Toys 'R' Us. That was my first story introduction to the franchise, and it provided essential information such as Serena being an ordinary girl "who just happens to own the world's most powerful compact". Yeah, the English dub is stupid, but I love it so.
I also got a VHS tape of the first two episodes, started watching the series early on weekday mornings, got the first English soundtrack album, got the second and third movies in English on VHS, got the first and second movies in Japanese on VHS, got the third season (the "S" series) on VHS from Wal-Mart, etc. Eventually, I started getting Sailor Moon on DVD, and I happen to own every Sailor Moon DVD released in North America, although some (mostly the English dub discs but also one of the Japanese R discs) have bad spots that make some episodes unplayable, and I shudder to think of what the replacement costs for these long-out-of-print DVDs would be.
(And, yes, I love the 2003-2004 live-action series. I left my computer on all night to download those episodes on dial-up soon after they aired in Japan.)
Anyway, manga. I got the entire original run in English as put out by Tokyopop. I've gotten into the fourth arc (the covers are branded "Sailor Moon Super S") and the equivalent spot in the anime. Yeah, after all of these years, I find it incredibly hard to slog through Super S. Way too much filler and focus on Chibi-Usa. I might just skip ahead to Stars for now.
The entire manga series has recently been re-released - along with the precursor series, "Codename: Sailor V". I have yet to get these, but here are some bits of info that might be useful:
This is an English translation of an updated version of the manga that was released to tie in with the live-action series. Technology was updated (CDs instead of floppy disks, etc.). I'm not sure of any other changes.
The original English translation called Sailor Moon "Bunny" and Tuxedo Mask "Darien". I believe the other Senshi (Scouts) were given their English dub names as well. (Sailor Moon is named "Serena" in the English dub.) I believe the new translation retains the Japanese names.