You may want to check out Kerry’s Magento Guide that is available via PDF and is printable - A great deal of work has been put into her guide and it focuses on the basics of working with Magento.
There are two free chapters available for download as well so you can get a feel if the work is right for you.
I don’t know about the user guide, but I have saved this link rom another post I came across for the ‘Designers guide’ which someone had taken from the wiki and converted to a pdf. You can get it here