Having a map of the available space and orientation is really important!

I'd add in the tree coverage, as this will severely impact you growing ability.

Here's my yard:

http://goldenoakfarm.us/BonzosPics/PublicAlbums/GardensAlbum1May1987July2003/gardenyardplanoutlinedandfinishednovember2008.html

This is an old map and doesn't show the 50' x 37' New Herb garden in the front yard. It also shows trees and gardens that used to be, and are no longer. I guess I need to update it....