Webdesigntuts+ has a thorough series covering Foundation 4 you might be interested in. If your a Lynda subscriber, they’ve got a couple of courses on Foundation 4, as well. There’s not a whole lot of difference between the grid in Foundation 4 and Foundation 5. Foundation 5 does add a new medium breakpoint which is great for tablets.
Man, the quality of the videos on Lynda.com always impresses me. But I don't wanna pay $25 when that's the only series I want. Wish I could just do a la carte.
http://www.webdesign.tutsplus.com/tutorials/htmlcss-tutorial...
http://www.lynda.com/Foundation-training-tutorials/1628-0.ht...