How do I put one image onto another? I need to put a pencil, a paintbrush, a set of music notes, and letters and numbers in certain specific places on the big smiley face I've drawn and saved. Also: how do I fine-tune the size of these images as I place them on the smiley face?
When you paste in Gimp, the pasted item is put on a temporary layer (Floating selection) that you can move and scale, among other things, before you "anchor" it to the target. You can also instead convert the paste directly into a new layer (Ctrl-Shift-N), and then move/scale the layer.
You can also add image files as layers (File > Opens as layers), and then move/scale them.
Warning; by default the Move tool moves the layer that is opaque where you click so make sure you click inside what you want to move and not next to it.