sprite comics look best in .PNG format. to save as a .PNG file when using paint (it's okay, many sprites are done this way), go to the save option (this doesn't work if you've already saved as another file type) and type this in the file name box:
filename.png
of course, replace filename with the name you want to use. to put it simply, just type ".png" (minus quotes) at the end of the file name when you first save.
this file type really helps with sprite comics, as it doesn't deteriorate or blur the image quality of pixel/sprite art like .JPG does.
How many times do I have to tell people not to do this comic type? -_-
Here it is anyway.
http://www.spriters-resource.com/nintendo/pokemon/