The banks are divided likeso:
1 bank for ALL the tileset information. As in, what type, attribute, and 2x2 tiles get drawn for each 16x16 metatile. The master game map is also in here.
2 banks for CHR of just BG tiles for the tilesets.
1 bank for sprite CHR data. Also has enemy palette info.
1 bank for the "other" screens like the title, menus, text, etc.
4 banks for level data
2 banks for enemy data
1 bank for information on how the enemy sprites are to be properly displayed. Also has information on player animations.
2 banks for music. (one only has one song though... ran out of space in the main one)
That's pretty much it. I'll be having one for cutscene information.