If you want I give you some tips for PSElements?
Its a bit different than to the full version, so there are some features not included, but you can work with it very good! Expacially for drawing and painting.
I use PSE 5, so please shout if you dont find any option!
Press CTRL and L to get "Level" - Control Panel. Play a bit and you will see what it is... I cant explain... O_O also not in my motherlanguage... If you put the the both outside arrows a little bit closer to the grey one in the middle you see a nicer effect.
The meaning of this: The data structure of your rough scan. Unnecessary grey pixel will disapear and your data (count of MB s) becomes also smaler. Dont use the arrows too much, because you wouldn´t see your drawing anymore!
If you use a grafictablet you can clean up the lines easily! I use my scaned scatches as a scetch layer, and paint the original lines on a layer above these scatch layer. Do you know how to use layers? (Many poeple dont know... so I ask)
There are some realy great options for them! Under my line layer i put the coloring-layers. But sometimes your linelayer is not only black/transparent but rather black/withe.
In your layerbox you will find the layer options (standard is "normal") use "multyply" and the grey level of your pixels will become the level of transparence. This means: 100%-withe pixels become 100%-transparent ones. 100%-black becomes 0%-transparent. "Screen" is the opposite of multiply: black becomes transparent and withe becomes withe.
I realy like this option!
This is only a tip, when you like to use it. It makes much things easyer!
If you have any question, only post a IM
I will try to help you, if I can!
And: GO ON! You can draw very good! Only training makes a drawing-ninja!