I like hogan's, too. I agree, they don't seem all that difficult to build. I have seen some beautiful roof/ceiling designs in museum examples.
I can't say I know that much about them, but there are plenty around here (near the Navajo res). We have friends with hogans, too. If you have any specific questions (or general too, I guess). We could try to answer or find out for you.
Nowadays, it seems most hogans I see going up are built using modern frame construction, sheathed in plywood. Loses alot, if you ask me. Anyway, here is a little of what I know about them (in the older stye) ...
The wood used around here was juniper (some people call it cedar) because, of the local woods, it is more resistant to rot, pests, and moisture. After being cut to length, they could be sort of saddle-notched, and laid out in an octagonal pattern. You go up that way untill you reach the height you want. The roof started as horizontal timbers resting on the walls. The next layer is put up so that their ends are near the centers of the previous layer. In this way, the span is shortened and the roof is framed in closer to the center of the octagon. The next layers proceed as explained, untill the opening is as big as you want it for a smoke hole, which is flap covered by whatever (animal skin, canvas). I believe the door was preferred south-facing, and at least some had their walls bermed or buried, except for the south face, keeping it 'cool in the summer and warm in the winter', as one friend explained.
The description above is for a female style hogan. Male style hogans are lean-to type construction. Around some main frame members (kind of a leaning-in box), smaller poles were leaned in a circular arrangement, and on top of these was plastered adobe. I also seem to recall some of these being at least semi-submerged, also.
Here are links you may find interesting...
http://home.earthlink.net/~pfeiffer/N-Navajo%20Life.htmlhttp://www.kstrom.net/isk/maps/houses/hogan.htmlp.s. I am no expert. Just sharing what I know. Some of it may be wrong =)
