This 'guide' is meant specificly for simfiles that are downloaded,
not those that you are trying to create.
These should more or less be the folders in your StepMania folder.
Right now we're only focussing on one of them - Songs.
This is the basic folder structure that your groups on songs should be in.
In this image - Songs being the base directory,
VirInPro - Zyb being the group directory,
and Gorillaz - Dare being the simfile directory.
Group and Simfile directories may be named literally anything
excluding symbols which computers don't allow.
These are files commonly found in simfiles,
although, four of these are not required.
The *.sm file contains the charts and song information,
this is the file that StepMania uses
to recognize your songs and play steps.
Can also be other step format files. Required.
The *.ogg is a music file, it can also be an *.mp3 file, required.
The *.png file is the banner, not required.
The *.jpg file is the background, not required.
The *.AVI is a video file, meant for the background, not required.
CdTitle-Zanaso.png is a CdTitle, it is not required.
Q: Do all songs need to be in this folder format
Unless we are talking about the folder format for the AdditionalSongFolders tag in the StepMania.ini, then yes. Very yes.
Q: Group and Simfile folders can be named anything?
Anything with no stipulations what-so-ever, whatever the filesystem will allow you to name the folders, they'll still work.
Q: The CdTitle and Banner are mentioned to be *.png format images and the background a *.jpg, what other image formats can StepMania use?
The only image formats StepMania can use are BMP, GIF, JPG, and PNG. Stick to PNG if you can, they have the smallest filesize with no loss of image quality.
Q: Videos? (anything regarding them)
Different FAQ, kthx. It isn't quite up yet.
Q: What audio formats does StepMania accept?
As far as I know - MP3, OGG, and WAV. Avoid WAV like the plague.
Q: You said that SM was the file that held the song information and the step chart data, but that there are also other formats, such as?
The only other file format whose extension I specifically remember is DWI. The extension's lettering stands for Dance With Intensity which is an older and now rarely used simulator of the same nature as StepMania but much less capable. There's also BMS and KSF. The only other format that I remember explicit being notified that StepMania could also use is from a nearly useless simulator for DDR known as Delight Delight Reduplication. I'm willing to learn about more.