The office of the President website has information in English about the role of the president, recent events and biographies of past presidents from 2000 onwards.
The Hungarian National Election office has background information on the electoral system, legislation . information from 1996-2008 . It doesnt seem to include presidential elections.
The Centre for the Study of Public Policy (CSPP), based at the University of Aberdeen, specialises in comparative public policy research. Since 1991 it has been conducting a unique programme of survey research in 15 post-Communist countries in Central and Eastern Europe and the Former Soviet Union. Information about Hungarian studies can be found on the website.
Project on Political Transformation and the Electoral Process in Post-Communist Europe based at the University of Essex also has some past data on parliamentary elections in Hungary
OSCE ODIHR has an online collection of information on the electoral system , the text of electoral laws and some election observation reports on its website
Erik Herrons website has an excellent collection of links to political sites and news resources relating to Hungary. These focus on sites based in Hungary.