I'm wondering how far the effect schools ahve goes (areawise). The first few attempts where I placed schools I had to put quite a lot within 1 "map cell" so that I get almost all people educated. Is there something I did do wrong or do schools (normally) have quite a large area of effect (and if so about how large)?
There are two factors to educational facilities. First their is coverage, also called efficiency. This is shown on the map by the colour of the streets of your city. Secondly, there is capacity. There are three different educational infrastructures with capacities of 300, 1200, and 4500 respectively. The capacity correlates with their coverage (the more capacity, the larger their coverage area).
When you place a new establishment, you want to look for the street's colour. The greener it is, the more efficient the school will be for that area, that is, the green area is covered by the school. When you investigate your city using the Info Views (top left-hand corner, second element on the right-hand column), there are three tabs, one for each educational building. You can then also examine the placement of schools by looking at the street colours, and see the availability, which basically just tells you how many of the available capacity is taken by your current citizens.