Welcome to the fire newguy.

My suggestion is you look out of each window in your house and see what you can see from them taking note of:
1. Possible cover (ditches, large trees, walls)
2. Possible concelement (shrubs, neighbor's windows, etc...)
3. Possible lines of attack (streets, alleys)

Then fire up Google Earth and use its measuring tool to measure the distance from each of your windows to the spots of interest you noted above. Print out several aerial photos of your house and draw lines between the windows and these spots of interest, and write the distance on the line. That way you know how to adjust your shooting to hit a particular spot. Mount these range maps near the windows and you are ready to go.

Side benefit: they make great conversation starters with your neighbors, babysitters, repairmen, social workers...

-Blast