School Eduction
Education is a service required by your citizens. Unlike other services, the effects of the different educational buildings are cumulative, not overlapping. What this means is that you'll need different types of schools at all times, not only bigger ones.
- Elementary school (1000/mo),
- Middle school (20000/mo),
- High school (5000/mo)
- Private school (10 000/mo).
Different schools have different coverage areas, with Elementary having the smallest, and High - the largest. The private school provides very good quality, but relatively small coverage.
You will need to create a network of multiple types of schools. The best thing to do is place a full network of Elementary schools, then alternate Middle and High schools throughout the rest of the city. Use private schools in those high-nosed Elites neighborhoods only. You'll end up spending much more money than with health, security and fire protection, but that's the only way of providing full coverage.
In the 'Education' construction tab you'll also find the various specialized educational buildings, unlocked through resource specialization of branches like a particular type of industry, or offices, or something else. Think of it as a specialized institute. Placing those will yield not only a vast increase of production in the relative sector, but also a 5% overall boost to education. So, it's money well spend. My advice is to use those whenever you can affor them.