Where did you save it? Do a system search with something like an8 as a keyword; windows should find it.
If the problem is just where it is saved, can't you get it back just using the file list at the bottom of the file menu? I read the post as the skeleton had disappeared from the file.
Hide and the
bones toggle both reset when the file is reopned, so I doubt that's the problem, but might want to show all, and push the bones toggle button.
Regarding tutorials:
It was a bit advanced, for me, but I'm going to give some things Soy Sauce mentions a try, since they look helpful. Looks like he has a number of tutorials, only I couldn't seem to figure out how to get YouTube to only display his. Thanks, Soy Sauce.