EURES-Portal: https://ec.europa.eu/eures/main.jsp?acro=lw&lang=de&catId=490&parentId=0

Visa: 
Visa types and requirements: https://www.expatica.com/pt/visas-and-permits/Moving-to-Portugal-Portuguese-visas-and-residency-permits_105233.html

Entry and residence requirements:
Ministry of Foreign Affairs: mne.gov.pt/...

Working in Portugal:
Eures - The European Job Mobility Portal: ec.europa.eu/...

Accommodation:
Rooms in Portugal: expatriates.com/...
Flats in Portugal: housing.justlanded.com/...
International Accommodation Agency: fineandmine.de/...

Country information:
Wikipedia: wikipedia.org/...

Further information:
Tourist Information: portugalvirtual.pt/...
Visit Portugal: visitportugal.com/...