Back in 2006 (seems a long time ago now) we wrote a quick WordPress manual for our clients. We gave it away, but it was targeted and not great.
This year we've just re-written the manual to bring it up to date and to also stick with standard WordPress behaviour. We still have some things we'd like to add but we're releasing it now for feedback. So far it's been very positive :)
The download (in pdf form) is here:
And we blog about stuff informally here:
I hope you find the manual useful.