Topic: looking for a site

(Assuming you want the layout to look something like this post #2691000)

NOTE: ctrl+z is undo. You'll need this a lot because GIMP is a pain in the ass to use.

1. Download GIMP on your PC, if you haven't already
2. File > New, select a Width and Height, and click Ok
3. Open the necessary pictures as layers by either:
3a. File > Open as Layers
3b. In a web browser with the image open, right click > copy image, open GIMP, ctrl+v
4. Similarly, open an image of a grid to use. ALTERNATIVELY, You could also draw the grid lines yourself. For brevity, I won't go into as much depth as other steps, but you would need to: create new layer, make sure that's the active layer, select the paintbrush tool (shortcut: p), adjust the brush size from the tools menu (hopefully open by default on the left?) or using [ and ], hold shift and use the mouse to click the 2 endpoints to draw straight lines.
5. You can double click the name of the layer to change it (the layers box should hopefully be open by default in the bottom-right?). You might want to rename them, so you know what is what. You can also click the eyeball icon to make a layer invisible and click again to make it visible. There's also a slider above the layers for Opacity, in case you want to temporarily make a layer semi-transparent to see what's underneath it.
6. If not done already, click the layer with the grid image in the layers box and drag it to the top of the list. This will make it display over everything else.
7. If the grid lines aren't the proper size for the image, click the layer in the layer menu to select it, then use the Scale tool (Shortcut: shift + s) and use the mouse to adjust its size. Press Enter when done. If necessary, click and drag the grid to the correct place with the Move tool (Shortcut: m)
8. In the layers box, click one of the layers with a character, then underneath the box, click the "create duplicate layer" icon (2 rectangles stacked icon).
9. Make all layers invisible with the the eyeball icons except for one of the duplicate layers from the previous step and the grid layer
10. Make sure the active layer is the one with the character. Select the face of a character with the rectangle tool (Shortcut: r) and click-and-drag from one corner of the face region to the other
11. ctrl+i to invert the select. delete to delete everything except the face. (This assumes the alpha channel is enabled for the layer. If not, undo, right click on the layer in the layer box, add alpha channel, and try again)
12. Invert the selection again with ctrl+i to reselect the face
13. Using the Scale tool (shortcut: shift+s), adjust the face size to the size it needs to be or slightly larger. Press Enter when done.
14. Select the Fuzzy Select tool (shortcut: u). Click outside the face to select the transparent part of the layer. Use ctrl+i to invert the selection, so you now have the face selected again.
15. ctrl+shift+l (creates a "floating layer") and click and drag the face to the proper location. Then click elsewhere on the image to place the floating layer back down.
16. If the face is a bit too large and you need to crop some of it off: use the Rectangle Select tool (Shortcut: r) to select the region where the face goes, invert the selection with ctrl+i and press delete to delete everything outside that region
17. Repeat steps 9-16 for each face and penis
18. Make all layers visible, except any layers you don't want to be visible in the final image
19. File > Export As Whatever-Name-You-Want-Goes-Here.png