This might help - a map of the current "re-districted" districts (zoom in for street details):
http://www.fcps.net/redist/0607Elem7....pdf?nc=060125
These are the 2006 primary schools. I admit I'm a little confused by the whole re-districting concept, but as I understand it you will attend your primary school unless that school becomes overcrowded - at that point you could be sent to one of four alternate choices.
Here is the general overview where the map came from:
http://www.fcps.net/redist/
Lots of good information there.