Did he name himself that, or did people of Metropolis just start calling him Superman and he just decided to go with it?

I mean it's kind of weird already with his S not standing for Superman. I personally like the idea of his name not being too coincidental. (Then again is a pretty obvious name.) I guess when I put it that way, the S should be the basis for the name. ("my costume says S so I should pick a name that starts with that letter")

Also, how in the world did he get a base in the north pole? He built it himself?

@zeello: Metropolitans came up with it.

Usually Lois Lane comes up with the name when she sees the S.
In New 52 Lois came up with it after seeing Superman in action.

Lois Lane names him

@zeello: Unless someone can prove me wrong, in the comics, Superman ALWAYS came up with the name and symbol by himself until Mark Waid's Birthright rewrite.

However, the S symbol being the crest of Superman's house was originally used by Richard Donner's 1978 Superman: The Movie.

@onemoreposter: Well you are half-wrong.

Usually Lois Lane names Superman. Yes the symbol is something that either Clark designed or inherit from his kryptonian parents.
In Superman TAS Lois Lane names him after his first appearance, in Superman: Birthright the same,in Superman: Secret Origin the same, in New 52 the same.
Modern tales of the man of steel tend to have him baptised by the woman he is destined to be with.

@squalleon: I am not half wrong. Nothing I said in my previous post was false. Lois never named Superman in the comics until Birthright in 2004.

Superman TAS was before Birthright a decade before...
EDIT: Oh sorry you said in the comics, then you are right
And did Lois name Superman in the old Superman movies, I don't remember?

because he is super, man.

@squalleon: She did. The emblem being the crest of his house and Lois naming him happened in the movie very much like it happened in Birthright.

Oh,Thanks!

Cause his Super and a Man

I mean his name basically describes him. his a Super-Ma. You know, kind of like Super-Hero.

I think it was Jerry Siegel and Joe Shuster who came up with that name. ;)

Then they made Metropolitans through plot twist to name Clark as such, and from there it’s became a tradition.