How do I save a project while I'm working on it?

I just lost several hours of work, after thinking that a) pressing command S was saving it (which, I now see there is no "Save" option in the "File" menu. Obviously, it's not autosaving either. :angry:

So, how do I save without quitting? Surely that's not the only way!?! :crazy:

If so, SAVING would be the number one feature I would expect for 2014 (and for every other prior year)! :exclamation:

And, why in the name of the Great Animator, when I quit after working on a previously saved project, does it prompt me to save (good), but then open the dialog to save under a new filename? :crazy:

I'm running Mac OS X 10.9.3.