Friends of mine built a really nice 10x12 smokehouse from dried pine logs on a cedar footing. If you are building your own from wood from the woods. Basically you are building a small box to larger (walk-in) cook shack.
Ensure that you skin and dry your logs. You should us tamarack or cedar for your footings as these types of wood are more resistant to rotting.

If using commercial lumber, don't use chemically treated wood for anything other than your footings.

Good links from google search.