I still sometimes find things I didn't know were there, by randomly mashing keys...
Most shortcuts can be found on the menus, or on the ~ list. There's also a shortcuts panel, but I don't get how you're supposed to scroll through the list while you're in an interactive mode.....
On a related subject, did you know CTRL+0 hides everything in Microsoft Excel, and CTRL+SHIFT+0 doesn't do the obvious (unhide everything), so you're stuck? Yeah, I found that out recently...
Tim