Generally food prices are reasonable - locally grown produce, in season,is cheap; but imported goods tend to be expensive. Bills - our electricity bill works out approx 70 euros per month (family of 4) and that includes local taxes (council taxes) and tv licence (obligatory and paid on every elec bill!). Telephone line rental costs 12.40 euros/month + 19%tax and cost of calls. Both electricty and tel. bills are issued every two months.
Regarding schools, the only full time English school in Crete is in Heraklion, the European school, and at present they only take pupils up to age 9. see http://www.livingincrete.net/schools.html
There is more detailed discussion in my book regarding schooling in Crete.
As a non Greek speaker your husband is very unlikely to find work as a civil engineeer in Crete. Building regulations differ the world over so it is unlikely that qualifications obtained outside of Greece for civil engineering will be certified here. You could contact the main building companies in Crete and ask their advice (put Crete + property into google and you'll find plenty of companies).