Start very simple, you are trying to climb a 5 mile near vertical mountain without experience. The folks taking those great photos have years of observing experience followed by years of astrophoto experience. It isn't as easy as the manufacturers want you to believe!

First pick up a copy of Covington's Astrophotography for the amateur. It will answer many of your questions. Wodaski's book is also highly recommended but I'm in the minority here in that I found it mostly to be a manual for CCDSoft and Maxim DL (he wrote both manuals and pulled about 75% of the book word for word from them). So if you use some other control program much of Wodaski's book isn't all that useful as he often uses menus from each in the how to parts of the book. It doesn't cover DSLR or planetary work with a web cam which are better staring points. Covington's book does but in less depth for CCD's. But it covers many of the basics Wodaski's book assumes you already know but you likely don't. To me it is better for the rank beginner. Then move to a more advanced book.

Next work on getting usable images from the DSLR mounted piggyback atop the C8. See the current issue of Sky and Telescope for a good article by Jerry Lodriguss. Covington has a good book on DSLR photography but it assumes you have already read the first book.

When you can get good shots using the DSLR and say a 400mm lens you will then be ready to move up to imaging deep sky through the C8. Still it is a big jump from 400mm to 2000mm. Things will get far more demanding. Just focusing is a problem. The focuser has to be ultra precise. Using an f/4 lens for instance you need to hit focus within 34 microns or about one thousandth of an inch.

For starters through the scope work on bright things like the moon and planets. For this a USB 2 webcam is the best choice with free Registax to sort through several thousand AVI frames, stack and process them.

You don't say what CCD you've ordered. Is it OSC or mono? Is it ABG or not? Did you match the pixel size to your focal length and seeing. Unless the CCD is small you'll need a compressor/flattener as a SCT has a very curved field of view so only part of the image on a medium size or larger chip will be in focus. Keep in mind a chip size of about 20mm diagonal is about as large as such a typical flattener/compressor can handle so buying larger is a waste of money with that scope. With the flattener and a matched CCD you can get great results but make sure the distance between the flattener and camera is correct. Otherwise it can really add more problems than it cures.

When ready for deep sky work taking many short one minute or maybe less exposures is the way to start. The results aren't great but are impressive to a beginner. I'd have killed for such results when using film in the 50's and 60's for instance. But read noise puts a limit to how many of these you can stack, after 50 or so you've reached a point of little gain. Once you get guiding (you'll need an off axis guider or a SBIG camera with internal guider chip) down you can increase the sub exposure time to 5 minutes or more and greatly decrease noise and increase image quality. You will be learning how to subtract darks, apply flats and normalize images along the way. Taking good flats can be an art in and of itself, especially without a good lightbox.

For now use the C8 for viewing while you do a lot of reading up and gain experience just using the scope, polar aligning it and learning your way around the sky. You really have to know the sky well to put a DSO onto a CCD chip. They have a far smaller field of view than your low power eyepiece and even a Celestron Goto mount will often miss the chip entirely so you have to know the area well enough to know what direction and how far to move the scope to find it. With something big and bright like the moon, no problem, with M57 it's a very different story!

For image processing there are lots of programs, IRIS, I too found hard to fathom. It was written in french and loses a lot in translation. I have a french speeking friend who said the french manual was far superior and cleared the fog making it usable. My high school french left me 5 decades ago! Personally I use CCDSoft to acquire, calibrate and normalize the images. Most of that is done as the sub frames are taken. When alignment is necessary I usually use Registar as it compensates for errors others don't. A SCT is very temperature sensitive so you have to refocus constantly. That can change the image scale a wee bit. Enough to color fringe stars. Other cheaper alternatives are available, just not as versatile. I use Photoshop with the FITS Liberator plugin for the image processing itself though I have added many plugins to it, some free some have a nominal fee such as the gradient removal one. Only CS and above is really good for this as it has far better 16 bit support than does earlier versions. Some do a lot of their processing in other programs like CCDStack and Pix Insight but most use Photoshop for some steps. Beginners can make far cheaper Elements and free Gimp work but they don't have all the tools or 16 bit support found in PS. I don't know if FITS Liberator works with GIMP. Probably does but I can't verify that. You need it or some other way to get FITS files into image processing programs that don't support FITS. IRIS does as do Pix Insight and CCD Stack as well as others. It's those not designed from the beginning for CCD work that lack FITS capabilities.

Anyway, you have a long steep road ahead so start slow and work up to the more complex stuff.

Rick