Maybe Not So Dumb After All
I hate the For Dummies series. The idea that you buy a book because you're stupid is simply insulting. How about calling it For the Curious? Is that so much worse? Anyway, it seems that there is someone with intelligence at said book publishers, since they've come out with the utterly improbably Linux Smart Homes for Dummies:364 pages and a CD-ROM that cover not only the typical X10 hardware and software characteristic of home automation, but also networking, video, audio, and even heating, ventilating, and air-conditioning (HVAC) control that can make your house the envy of your neighborhood.
Update: And here's the author's blog, with lots of useful stuff about Home Automation using GNU/Linux (with thanks to Neil for the comment below.)