First:
* Check out http://www.Google.com - the search engine ...
search on the term "dog house plans" (use the quotes) ...
you ought to get a LOT of ideas there. Some for free; some want money for the plans.

Second:
* Check out your local Lumber Yard, Home Depot, Lowe's, 84 Lumber, any place you
can buy lumber and building supplies ...
They usually have a rack of "Projects" - often including Dog Houses.

Third
* Try the local Humane Society or Dog Rescue ... they often pass out a dog house
Plan flyer with new adoptions.

Key Points:
* UP Off the ground with the floor - so there's an air space between the ground
and the floor
* INSULATED with double walls - to stabilize the temperature.
* Heavy Carpet nailed over the doorway - easy to open + stops drafts
* Almost Flat roof - sloped to the rear for drainage ... doubles as a sun porch.
* Roof Overhangs on two or more sides - gives shade in the summer

Happy Home Building!

PS: When You're Home - Fido should be INSIDE WITH you!