I good place to start is http://www.greatschools.net.
It is a national site that will give you information regarding test scores, demographics, etc. Often times there will also be parents who will write reviews of the schools as well. This can help give you and idea of the schools. I found greatschools.net very helpful for me when I was investigating elementary schools for my children. It is a good first resource to give you an overall picture of the school.
If you are working with a Realtor in the area, you could also ask them for contacts of parents in the area to see if you can talk to parents first hand regarding their experience in the schools in Arleta.
Alain Pinel Realtors