Are they not available until they make the site? I don't see a download option anywhere.
I assume you mean this submissions forum (http://forum.ninsheetmusic.org/index.php?board=36.0)? If you click on any of the submissions, there should be a couple of download links in the OP that'll give you the midi, pdf or mus for that submission.
Oh they weren't appearing for me before.
They're only available for you to download if you're logged in.