Google's advanced search allows you to search by domain name (on bottom line of the advanced search form).
Entering .edu or .gov into this line will only return results from educational or US government sites, which tend to contain more reliable scholarly or factual information. You will still have to evaluate the sites for authority, accuracy, currency, and objectivity. See- CRAAP TEST from the Meriam Library at the California State University, Chico.
There are many Internet gateways and resources that provide high quality education information. Some of the ones we recommend are:
Classroom Resources
Teacher's Resources
Research, Statistics & Reports
Information on Policy and Laws
Information on Students with Special Needs (minority students, children with physical or mental handicap, children with learning disabilities)