I don't think there is a Dummies Guide to the K1. But I think you will soon get used to the little guy and his menu system. If you have any specific questions on the K1 ask me via direct e-mail, or join the Elecraft Reflector and ask on there.
With mine, I have a 4 band board (40/30/20/15) and a 2 band board (80/40). Unfortunately, the 4 band board has been discontinued by Elecraft due to difficulties obtaining the trimmers. They have also discontinued the wide range tilt stand.
When swapping boards that have the same bands on both boards, as mine have, it is necessary to re-set the calibration on the common band. Another hint/tip, swapping boards when you have the internal ATU can be tricky, putting a thin rubber band through the spacers avoids them slipping off.
My K1 has the Elecraft backlight modification, which is nice. I also added a Cumbria Designs X-Lock to stop the VFO drift. When using the 80/40 board I add a couple of additional capacitors to the ATU via removable links, this increases the tuning range on these lower bands. Details of the X-Lock and ATU mod at: http://www.qsl.net/g4aon/elecraft_mods/
The mods are easily reversed if need be.