PCLinuxOS 2010.12 was my first venture into KDE 4.5. I found the special KDE edition of the magazine issued 17 Sep 2010 to be particularly helpful.
http://pclosmag.com/index.php/component/content/article/29-the-cms/75-kde-4-sc-special-editionI downloaded the pdf version and then created a link on the desktop. Thus, when I wish to look up something about KDE 4.5, I click on the link and up comes the magazine.
Along the bottom of the desktop, just above the panel, I have, in order
KDE 4.5, Home, Libre Office, Thunderbird, Firefox, Google Earth, Digikam, and finally Trash.
This arrangement makes the desktop a real joy to use.
Thanks to parnote and others for the special issue of the magazine referred to above.
Jim