New user feedback: How about starting with a link to where to find the Quick Start User Guide? When I saw your post, I went to take a look at the Guide and couldn't find it.
The Calibre client Help button takes me directly to the User Guide.
It's not mentioned on the Calibre site Help page at all (although these fora are).
http://calibre-ebook.com/help
A Google search ("calibre quick start user guide") turned up a couple of links that looked promising, but proved to be defunct links to the bug tracker.
e.g.
http://bugs.calibre-ebook.com/raw-at...20Schember.pdf
Oh -- or is this a guide that's available here on MobileRead?
ETA: DOH! I *just* stumbled across the Quick Start Guide as an ebook in my Library. I feel like a goof. My apologies.