I think I have all the information on building a grindbygg that I can practically get without actually traveling to Norway. The book I ordered from Norway, Grindbygningen, arrived yesterday, and I saw two books through ILL at the library. While the books answered several questions I had, they also posed new ones.
The post, tie-beam, and rafter-holder are the three most critical structural members. While the cuts are placed so as to stabilize their interlocked arrangement, too many cuts can compromise their strength. I have decided to take a middle path between the design of a primitive longhouse and the fully developed grindverk construction method when I build my shed. This photo illustrates how very few cuts are made to these three members - the post and tie-beam are obviously cut in the traditional grindverk method, but the rafter-holder has no visible cuts aside from diagonal braces (though not visible I assume they are present) and no coresponding cuts are made in the post and tie-beam to accomodate the rafter-holder. Instead of cuts used to hold the rafter-holder in place, it is wedged in place using an additional piece of wood that is fastened on the tie-beam next to the inside of the rafter-holder. Simple and effective.
I have since (as of 5/22/08) come up with a plan that utilizes additional grindverk techniques, while allowing for strength where there are lap joints along the rafter-holder.