I don’t do a lot of website development for clients, but when I do, I use WordPress.
For several years now, I will provide my clients with a PDF copy of EasyWPGuide, which is available for free! There is also an online version.
The manuals were recently updated to reflect the changes in WordPress 4.2.
Anthony Hortin, the author, writes:
“I created the Easy WP Guide for WordPress consultants to give to clients as a form of training. I know it’s not always possible to physically go to a clients location to provide them hands-on training. Instead, give them a copy of my popular WordPress manual and in simple, easy to read language, you can teach your clients how to use their new WordPress website.”