There are a number of rental websites you can utilize in your search:
This map will show you the various neighborhoods of Fremont:
As far as finding a "good" middle/elementary school area home to rent, I would recommend you use www.schoolandhousing.com as they have the most user-friendly website I have come across. Besides the fact that they include private schools, what is really nice about their website is that it also shows performance information for the elementary/middle/high schools a specific property address is assigned to.
You should always call the Fremont Unified School District office to confirm the attendance schools before entering into a rental agreement. http://www.fremont.k12.ca.us/Page/274