How I did it

The Windmill started out life as a simple Cylinder. Which was extended too the height of the Windmill. Using Insert Edge Loop tool I added where the Windmill levels were meant too be. Using the scale I was able too pull the Cylinder in making the basic shape of the Windmill.

Using the extrude face tool I was able too shape some rooms into the side of the windmill, plus make the windows. I also added the roof and the doorway in the same manner, cutting in too the side of the Mill for the door and making an archway, the roof I extended upwards then pulled the vertices down the side and pulled the middle one up too make a point in the roof.

Using the smooth tool, I smoothed the bottom of the windmill out, too give it a curve. I extracted some more faces too add some detail too the outside, such as a band around the mill which were including in the design.

The prop was built using the same techniques, it started out as a Cylinder. Which I applyed the loop edge too and extract faces too make it into what it looks like now. I encounter some problems with the props, faces doubling up and hidden inside the shape. So I went into wireframe mode and deleted all the faces that weren't needed and sovled the problem.

The other problem I encountered was with the Booleans. When I went too use Booleans on the windmill too either cut into the mill or combined the meshes together I had all the selected objects, including the Mill, just disappear. I found out the reason for this was cause the Windmill had holes in it's structure. Which I did put there myself. Booleans can't deal with holes in a polygon when doing any boolean commands. So I had too manual cut into the Mill and combind objects with the mill. This problem did set me back a bit time wise, but I managed too get around it.