Ivysaur is definitely cute with the leaf on its head. :3

I'm curious what your process is on scanning and lineart. Do you scan it as pencil? Do you do the lineart in GIMP, with a gray line? One thing that can be really nice when scanning things is a nice, dark pen. Like an inking pen or something, although even something like a thin sharpie could work in a pinch. (I would advise against ball-tip pens, because they can be reflective in scanners sometimes.)

Without a tablet, good inking can be very important if you're doing scans, because it gives you a good base (plus you can erase pencil). Little "speckles" like those white speckles you see by the lineart are what happens if you try to flood fill when there are pencil flecks or something blocking the flood filling. On GIMP, you can go to Tools -> Brightness-Contrast, and then up the contrast a lot and maybe brightness a little. Use your mouse/touchpad to erase any straggling flecks or patches left over, too.

I think that, when coloring, finding out your method for lineart will be something that will serve you well as you continue your quest. 491 to go! (If you plan on doing it all within 2 months, that is, heheh.)

don't rush to shade stuff. work on basic stuff first! lots and lots of sketches and simple stuff. shading and coloring can come later!

this ivysaur is really cute! the cross eyed look is adorable and the leaf is a cute idea too.

This one was my favorite. XD