Pixel-Craft

You have to be a member to submit art (though, there are some groups that allow non-members to submit art). Just click on "contribute art" (at the top of this webpage), a window will open up in the gallery showing your deviations and a drop-down menu of the folders available. Choose whichever deviation you want to submit to the appropriate folder, after submitting it'll either say that it has successfully submitted or that it's waiting approval on the deviation you chose to submit.