I used to be very good with MS-Paint when I used Windows XP. When I switched to linux, I didn't find a single program that has equivalent functionality with equivalent ease, though there are many (including GIMP) that can do much more but the basic stuff (MS-Paint level) isn't as easy (e.g., the pixel perfect precision, Pinta by default does some blurring so pixel editing needs tweaking it a bit). Is there any guide…
It's much more powerful than the old paint program, but much simpler than Gimp. It only works on Windows though, so it may not work for you.