Purpose Images to Use Files to Include
Foreground Map16 page screenshot, in-game screenshot .bin file, palette file, .map16 file
Background .bin file, palette file, .map16 file, sample level
Sprite Tile editor screenshot, in-game screenshot .bin file, palette file
Player .bin file, shared palette file
Layer 3 .bin file, .stim file, palette file
Overworld .bin file, sample IPS
Font .bin file
Miscellaneous The relevant images for the type of submission it would be The relevant files for the type of submission it would be
Graphics Hack Map16 page screenshots, in-game screenshots AllGFX.bin (if applicable), .bin files, palette files, .map16 files, sample levels

Screenshot Howto
In-game ZSNES - press F1 then press down until "Save Snapshot" is selected. Ensure that the file type is set to PNG.
Snes9x - press Alt+F9 to see what hotkey is for saving a screenshot.
bsnes - select "Tools", then "Capture Screenshot".
Tile editor Press Ctrl+Alt+"Print Screen" on your keyboard with the tile editor selected, press Ctrl+V to paste the screenshot in an image editor, then save the image.
Map16 The same as a tile editor screenshot, except you do it with the Map16 Editor window.