to resize the skeleton
select the layer it is in. press CTRL-T. A box will form around in.
Hold SHIFT and click one of the little squares at the corner. holding shift will keep the aspect ration intact. Get it lookin good.
to make it snap to middle, go to view-> snap. This SHOULD make it snap to those little lines you see splitting the image up.\
NOTE
changing the size of the skeleton is
OK as long as you keep the aspect ratio. the arrow and poi locations can be adjusted all at once. its too easy
to do colors
turn off visibility on all layers except the skeleton. Do this by clicking the eyeball on the layer window.
Go to Layer-> New Layer. this layer will hold the color
using the magic wand, select the area you want colored. Usually works best with the anti-aliasing checkbox CHECKED.
with that area selected, go to the paintbucket. Select a color, fill in that selected area.
deselect everything by pressing CTRL-D
double click that layer in the window layer. This will bring up the layer blending properties window.
go down to pattern overlay
select a fitting pattern. Make the opacity like 4%
I suggest
making a new layer everytime you color something different. ie one layer for buildings, one for the grass, one for water
let me know if it all makes sense!