Thanks ^.^
For sharing, the best way to get better is tons of practice, but there are some things that help to think about. If you're looking to improve on where to shade, starting out with shading in solid colour would be good to give you a clear idea of where the shading is.
I think the key thing to think is that you shade where the light can't reach. So, first you need to imagine a light source, say coming in from the top-left. Now try and think where the light would hit, and where it wouldn't, and shade accordingly. This only gets easier to see, and anothe way to help improve this is to look at how light affects things in nature. So, every one in a while, look at something and see how its shading is affected by the light; it really helps.
Also don't forget that parts of a picture can cast shadows onto other parts, so like a tail coming out from behind an animal would have a shadow cast onto the body if the animal is facing the light straight-on.
So basically, draw, look at how it works in life, draw, imagine a light source, draw, keep drawing and have fun n_n
good luck!