You don't need to age deer however it cuts up better if the meat "sets up"....IMO....If temps allow, I'll skin it as soon as possible, you need to get the body cavity hung, skinned and opened up to cool. The faster you get the organs and blood out the better the meat will be, again, if temps allow I'll hang it overnight to set the meat, butcher it the next day. If temps are high and bugs are out, process immediately. I just find the meat cuts nicer after the day, again if temps allow.