I have butchered my own for years. You' ll need a few good knives and that' s about it. Keep a sharpening steel close at hand to touch up the knives regularly. It would really help you to watch a video or 2 and to have someone experienced there when you do your first few deer. After that it just experience. Some use saws but I have eliminated the use of a saw from my butchering.
I don' t deal with sausage but I do my own grind I really like the taste of venison and if I' m going to introduce other flavors into a sausage I' d rather just use beef or pork to make the sausage and save my venison for the grind, steaks, and roasts. I have been doing more and more grind lately.
I steak out the backstraps and eat the tenderlins whole. I steak out some of the top round and sirloin and only keep the neck (2 pieces) and the shoulders as roasts. The roasts are slow cooked and then used in stews. Pretty much everything else becomes the grind with about 7-8% beef suet for moisture and a tiny bit of beef flavor.