Databases and sources of information

http://scholar.google.com/
Google scholar enables you to search more efficiently for scientific articles

http://ideas.repec.org/
IDEAS is an elaborated database for economists, which offers work papers and articles of journals free of charge.

http://www.destatis.de/jetspeed/portal/cms/Sites/destatis/Internet/EN/Navigation/Homepage__NT.psml
The website of the German Federal Office for Statistics, always good for numbers!