Image Processing
I cuurently use wxAstroCapture for image capture from the Atik 16 ic-s camera, and EOS Utility for the Canon 350D.
For stacking of images I either use Deep Sky Stacker, or Registax.
For image processing I use a combination of Photoshop (CS2), Gimp, and PixInsight LE.
There are plenty of guides on the web on how to stack images once you have captured them and then how best to process the results