I need to know specifically the minimum dimensions for a circular
sweat hut assuming a 24" diameter pit in the center to hold the heated
stones.  Is an eight-foot diameter (three feet around the pit) too
small?  Any detailed directions for constructing a sweat hut would be
a plus.

An eight foot diameter seems to be the minimum, Charlie, given a
two-foot diameter pit. There are a number of "Building a Sweat Lodge"
pages.  This one at...

http://www.sagemenscircle.org/buildlodge.html

...notes, "a practical lodge about 8 feet in diameter will hold 4-6
people." with "a small pit about 2 feet wide in the center of the
lodge." As you'll see, the page has detailed instructions for building
a hut/lodge.

According to "Building a Sweat Lodge" at...

http://www.think-aboutit.com/native/building_a_sweat_lodge.htm

"Sit cross-legged on the ground facing the [rock pit's] outer edge ,
and leave at least a foot or two between your knees and the center
[rock pit's] outer edge." The guide recommends a minimum nine-foot
diameter lodge which "will seat twelve people comfortably" using a 24"
diameter pit. The page also goes on to give detailed instructions on
building a sweat lodge.

Two other pages dealing with  sweat lodges or hut you may find of
interest...

http://www.welcomehome.org/rob/sweat/sweat.html

http://www.indiancanyonvillage.org/SweatLodge.htm (many links on this
page.  Unfortunately, many are also broken).

regards,

rico

Excellent information!  Thanks!