A couple of image processing links
Here are a few links to other astro related sites that deal with processing astro images
http://www.atalas.net/index.php?option=com_expose&Itemid=4 Has a few nice, simple video tutorials that deal with the main astro imaging tasks of stretching, enhancing colour and start repair.
http://blog.deepskycolors.com/archive/2010/04/26/hasta-La-Vista-Green.html This site has a free plugin for removing the green cast that is a problem mainly in images obtained through a light pollution filter.
http://www.dl-digital.com/astrophoto/p2-astro/Astro-Workflow.htm Use lab colour to sharpen and boost colour.
http://darkhorizons.emissionline.com/PSDDP.htm DDP For Photoshop
http://www.iceinspace.com.au/projects.html A whole list of image processing links!
http://bf-astro.com/eXcalibrator/excalibrator.htm Not tried this yet but it claims to look at reference stars in fits files and will then work out the correct colour balance to apply to an image
http://www.starshadows.com/documentation/index.cfm?DocID=3 Photoshop processing hints & tips