Great article on beginner astrophotography options, on using equipment you may already own to do something interesting. (via Reddit) Some ideas to follow up:
Try using a Barlow to change the focal point on my 8″ Dob, so I can do prime focus images with the old DSLR I have knocking around. Apparently this will work, although the weight and balance may be a problem.
Look into software to manage DSLR focus. The article recommends APT but that’s windows-only (maybe Wine?). Nebulosity looks promising on a Mac. More software options in this old list.
Read the /r/astrophotography FAQ.