One method for connecting a digital camera to a telescope for imaging is to use a T-Mount adaptor for prime focus, or you can connect the camera afocally and use an eyepiece for greater magnification. These adaptors come in a variety of shapes and sizes for 1.25" and 2" focusers. This method is also known as eyepiece projection.
The adaptor typically splits into to sections, the inner and outer tubes. When split in two an eyepiece will fit inside the inner tube and secured in place, then the outer tube slides over the top and is again secured with screws. One end of the adaptor fits into the focuser eyepiece slot, while the other end attaches to the T-Mount and camera.
So far I haven't had much success with my adaptor. I found it near impossible to focus as their just isn't enough travel in the mechanism, or the fully extended focuser and fully extended adaptor and camera put a huge strain on the mount and focuser base. I also found that the image in the camera viewfinder is so faint that I can hardly see what I am trying to photograph.