I'm helping a bit with spriting for some game in development and they need a tilemap. Can anyone tell me what they are and how to make them? I searched for guides online but couldn't find any

Sounds like hes making as tile based game. If you're making sprite for him, they will be tiled.


You'll need to make lots of different sprite, all the same size. Those sprites will eventually be 'tiled' (placed next to each other) to from a level/character/ect. All art in tile based games, are made with tiles.
You need to ask him what size he wants the tiles. 64x64, for instance. All tiles must be the same size.