In addition to EUR-Lex - the official source for European Union law on the internet - you can now also use Amicuria (European Union law at your fingertips) to search for cases, legislation, treaty articles and Official Journal publications. The search option for cases on name or part of a name is particularly useful if you do not have the case number at hand.
The search engine is a product of Dieter Kraus - Head of Cabinet at the European Court of Justice.