bwrangler, who posts here often, has some instructions on his sitehttp://bwrangler.madpage.com/bee/gobh.htm
it's not really a Van Frisch type like you mention, his is several frames thick
I guess a Van Frisch type is better because you can see every surface but one like this is more viable over time.
I modified his design and built thishttp://drobbins.net/bee's/Dsc00958.jpg
it's really pretty easy, just a box, depends on how fancy you want to get.
You gotta make the grooves the frames fit in, the proper tool is a dado blade for a table saw, but you could fudge it with a skill saw.
I figure if I put frames in the center (it's 4 frames thick) and frames with starter strips on the ouside, I'll be able to watch hive development very nicely
Here's a Van Frisch type http://www.beesource.com/plans/obsrhive.htm