i'm new at this too, we just went gf/cf about 2 weeks ago.
i've been making rice milk kefir for a little while (a week?). it doesnt act the same as cow milk kefir, ie it doesnt get thick, so i let it sit until the whey separates out. it gets made into popsicles, so i figure it doesnt really matter if it overprocesses. i was just reading sandor katz's book recently, and it sounds like he's made kefir out of just about anything you can think of (even gatorade!? definitely something we wont be trying out!) that's liquidy and has some carbohydrates in it for the kefir to feed on.
there's a cashew yogurt recipe here: http://www.pecanbread.com/recipes.html
(about 2/3's of the way down the page) i plan to try it as soon as a get a chance to scout out a source of non-dairy yogurt start.