I believe wxAstroCapture works with the Celestron NexImage camera - you can download from here:
http://arnholm.org/astro/software/wxAst ... /index.htm
and there is a very helpful yahoo group here as well:
http://groups.yahoo.com/group/wxAstroCapture/
The guys there are extremely helpful and I'd thoroughly recommend trying it out. It's free and works on both Windows and various Linux systems. Another option would be to try K3CCD. There's a free version (version 1 I believe) and a commercial version available. I've used this in the past with great success as well. You can download from here and it also has a yahoo support groups:
http://www.pk3.org/Astro/index.htm?k3ccdtools.htm
http://groups.yahoo.com/group/K3CCDTools/
We also run a yahoo imaging group at the society as well, so feel free to join us over there for discussions on imaging, processing, and many other related topics:
http://groups.yahoo.com/group/BASImaging/
Hope this helps - let us know how you get on! Always good to test new software thoroughly to get used to it and make sure it all works when inside in the warm before venturing outside ... if it can go wrong out there, it probably will!
Simon.