Press the S KEY for scale.
Hold the Ctrl KEY.
Move your mouse in towards the center of the tower.
Another way to make sure you scale correctly is to watch the numbers in the
corner. Keep moving your mouse to the middle until your scale reads 0.
Press the A KEY to deselect all.
Press the B KEY to use
the selecting tool Select all the vertices at the bottom of the tower.
Right click to exit selecting mode.
Read all of this before
doing anything. Press the E KEY
for Extrude. Click Only Edges.
Immediately after that press the S KEY
for scale. Move your mouse in towards the center of the cone a little.
Once you move it in a little click.
Press the E KEY again
for extrude. Click Edges.
Move your mouse down about 3 units.
Press the E KEY again
for extrude. Click Edges.
Move down about 1 unit. 
Press the S KEY for
scale and move away from the center of the tower.
Read all of this before doing anything. Press the
E KEY for Extrude.
Click Only Edges.
Immediately after that press the S KEY
for scale. Move your mouse in towards the center of the cone.
Try to move in the same amount as the tower above.
Press the E KEY for
extrude. Click Edges. Move
down 9 units. You will have to zoom out for this.
Click Object Mode.
Click View.
Click Top.
Press Spacebar > Add > Mesh >
Circle. 
Set the vertices to 5
and click Ok.
Press the S KEY for
scale. Drag away from the center of the pentagon. This will make
the pentagon larger. You want something like this picture.
\
We need to rotate the pentagon. Press the
R KEY.
Hold Ctrl and Shift at the same time. Move your mouse
around the like a clock until you have rotated 27 degrees.
Click the triangles next to Edit
Mode. Click Object Mode.
Right Click the first
tower. It should turn pink.
Press the G KEY.
Move your mouse and the tower will move to. Move the tower to one of
the corners.
Press Shift D.
This will duplicate the tower. Move your mouse and you will see the
next tower. Place it on the next corner. Do this for all five
corners.
Right Click the castle
wall so it is pink.
Right Click the
triangles next to object mode. 
Click Edit Mode on the menu that pops
up. 
Press the E KEY for
extrude. Click edges.
Immediately after press the S KEY.
Move your mouse in to create the wall of the castle.
