First off, be careful of your cropping... some of the shots have parts of the aircraft cut off for no good reason.
Second, if you're trying to get your shots on a.net, I'd give up shooting at the long end (200mm+) of the lens you're using. Cheap(er) lenses are notorious for having sharpness fall off the closer to their maximum reach they get, and it looks like yours is no different - most of these shots are really really soft. You'll either need to get closer to the aircraft, or invest in better glass.
Third, your settings (aperture, shutter speed, ISO, etc...) seem to be ok for most of the shots, but make sure your aperture stays around that oft-mentioned range of f/8-11. If you venture outside of that range with a cheaper lens, you're asking for poor results.
So to sum up, you could crop a little better, but most of your poor results (for a.net anyway) are mostly likely due to the fact that you're trying to get a cheap lens to perform like a much more expensive one (shooting at the long end, using wide open apertures, etc...).
As for editing, that's not even worth mentioning at this point, as the shots you've posted so far aren't even close enough in quality (for a.net) to warrant trying to edit.
a) as mentioned above, try to get closer to the action (probably not possible) so that you're not over-extending your lens' capabilities
b) think about getting a better lens
c) be content to keep these and any other shots for yourself, but perhaps not worry about trying to upload them to a.net.