General Information:
EU-Community: http://eu-community.daad.de/index.php?id=62
EURES-Portal: https://ec.europa.eu/eures/main.jsp?acro=lw&lang=de&catId=490&parentId=0
General Tips: http://karriere-journal.monster.de/bewerbungs-tipps/international/bewerben-in-irland-41370/article.aspx

Visa: 
Visa types and requirements: https://www.dfa.ie/travel/visas/visas-for-ireland/

Entry and residence requirements:
Department of Foreign Affairs: foreignaffairs.gov.ie/...

Social insurance provisions:
Department of Social and Family Affairs: welfare.ie/...

Insurance:
Health Service Executive: hse.ie/...

Tax regulations:
Citizens Information: citizensinformation.ie/...
Irish Tax Institute: taxireland.ie/...

Accommodation:
Just landed - Housing & Rentals: justlanded.com/...
Ireland's Biggest Property Site: daft.ie/...
Bed & Breakfast: ireland-bnb.com/...
Bed & Breakfast: irish-net.de/...

Country information:
Wikipedia: wikipedia.org/...
Culture Crossing: culturecrossing.net/...

Further information:
Tourist information: lookintoireland.com/...
Discover Ireland: discoverireland.ie/...