Skinning and Tanning isn’t that difficult – disposing of the remains (guts, etc) if you’re not going to cook them, must be done properly in DC. I personally recommend the SAS Survival Guide – they have excellent instructions. i also recommend NOT doing it on your own property as it can be quite messy and the flies are atrocious – although you might fare better with that now in the Winter. Good luck.
ps – start with a rabbit, they are easier than squirrels