In Montgomery County, your kids generally have to go to school in the home district. There are exceptions for magnet programs and consortia.
I'd start with your home school, which you can find here:
http://gis.mcpsmd.org/gis/Publiclocator.asp
And then look at special programs available to you based on your location:
http://www.montgomeryschoolsmd.org/curriculum/specialprograms/