During my planning of a new tufa garden, I've come across a variety of information sources on the design and construction of tufa gardens. I thought I'd share them here. My focus here is in-ground gardening, as opposed to container gardening.
Lowe, Duncan, Growing Alpines in Raised Beds, Troughs and Tufa. Batsford 1991. [I haven't actually seen this book. Have any of you?]
NARGS Forum
"The making of a tufa garden" http://nargs.org/smf/index.php?topic=240.0
"High desert tufa bed" http://nargs.org/smf/index.php?topic=1023.0
Scottish Rock Garden Club Forum
"Construction of a New Tufa Mound in the Rock Garden" http://www.srgc.net/forum/index.php?topic=7049.0
"Tufa Ideas" http://www.srgc.net/forum/index.php?topic=1670.0
"Building a Tufa Cliff" http://www.srgc.net/forum/index.php?topic=4842.0
Alpine Garden Society Forum
"A New Tufa Bed" http://www.alpinegardensociety.net/gardens/AGS-garden/news/A+New+Tufa+Be...
Rock Garden Quarterly
"Renewal of the Mary Azary Rock Garden, Michigan" by David Michener. Rock Garden Quarterly 67(2):129
"Building a Tufa Cliff" by David Sellars. Rock Garden Quarterly 69(4):364
"A Tufa Garden in Alaska" by Carmel Tysver. Rock Garden Quarterly 70(4):378
International Rock Gardener
"Czech Tufa King in Bavaria" by Zdeněk Zvolánek. May 2010
"Mountains in the Gardens: Second Report from the Tufa Kingdom" by Zdeněk Zvolánek. April 2012. Available online http://www.srgc.org.uk/logs/index.php?log=international
Adirondack Chapter NARGS
"Tufa from the Ilion Gorge" by Bill Stark. Green Dragon Tales February 2013. Available, at least for now, on the chapter's web site http://www.acnargs.org/
Wrightman Alpines
"Tufa Gardens" http://www.wrightmanalpines.com/blog/harvey/2003-12-10/tufa-gardens
"Clay Crevice & Cleft Construction" http://www.wrightmanalpines.com/blog/harvey/2009-07-10/clay-crevice-clef...
Videos: "Josef Halda—Building a Crevice Garden," "Planting with Tufa," and "How to Create Clay Crevices in a Rock Garden" http://www.wrightmanalpines.com/video
Wild Ginger Farm
"How to Build A Tufa Rock Garden" http://www.wildgingerfarm.com/BuildaTufaRockGarden.htm