EU institutions and other bodies - overview:
https://europa.eu/european-union/about-eu/institutions-bodies

European Parliament: 
http://www.europarl.europa.eu/portal

European Council:
http://www.consilium.europa.eu/en/european-council/

Council of the European Union:
http://www.consilium.europa.eu/en/council-eu/

European Commission:
http://ec.europa.eu/index_en.htm

High Representative of the Union for Foreign Affairs and Security Policy: 
http://ec.europa.eu/commission/2014-2019/mogherini_en

Court of Justice of the European Union: 
https://europa.eu/european-union/about-eu/institutions-bodies/court-justice_en
http://curia.europa.eu/jcms/jcms/j_6/en/