GoodSchoolsGuide.co.uk offers you a tool that will help you find a school closest to your area.
Go to their Find a School page - this area will let you search using the name of the school or using a postcode.
The result will show you various schools in the nearby areas. Just click on the name of the school and you will be given a chance to see if that particular school has an available catchment area map.
Also, FindaSchool.info will show you predefined school catchment area maps (subject to availability).
Additionally, you may also contact your local council to find out info about a school.
For more help, search the official database of schools in England at Gov.uk.
Read advice about league tables, types of school, applications and appeals and school transfers at BBC.co.uk.