I lived in Edwardsville for 2 years and I prefer Edwardsville to Belleville, because I like the college environment. The schools in Edwardsville score a bit better on ACT and state scoring, or they did when we looked - but that was 8 years ago.
Here is the Chicago Tribune ranking for 2012
http://schools.chicagotribune.com/school/belleville-high-...
http://schools.chicagotribune.com/school/belleville-high-...
Even if your kids aren't in high school- these are important numbers. unless the grade school has made DRAMATIC shifts.
It looks like Belleville West has better scores.
Remember when you are looking at this compared to STATE average - that Illinois ranks in the bottom 5 because of Chicago distirct. So you can be WAY above state, and still not acceptable. Illinois is very different that way.
That being said, Belleville is a fine area. There isn't much in terms of commerce - it's considered a "bedroom" community because there isn't a giant source of income that is within the city limits - therefore most people are communting to Edwardsville or St Louis... or they work in retail / saltellite buisnesses located within Belleville.
Here is the city data report
http://www.city-data.com/school/Belleville-Illinois.html#HS