I want to....
Find EU policy in a particular subject area.
Start on the European Commission website http://ec.europa.eu/index_en.htm under “Policies”. This will take you to the site of the individual units of the commission which often have really good overviews of legislation and EU actions.
Find a document by regulation or directive number.
Legal documents are all found on the Eur-lex website http://eur-lex.europa.eu/en/index.htm. Search “by document number” to find regulations and directives. COM documents are found under “Collections” and “Preparatory Acts”.
Find a document by Official Journal citation.
Legal documents are all found on the Eur-lex website http://eur-lex.europa.eu/en/index.htm. Search “by OJ reference”. The online OJ is linked to a PDF which is a page image of the print.
Find ECJ case law.
The best place to search ECJ decision is on Westlaw (EU-CS) or Lexis (Eurcom;ECJ). The court itself also has a website http://curia.europa.eu/ which is better than Eur-Lex but not as good as Westlaw or Lexis.
Find the legislative history of an EU law.
Pre-lex http://ec.europa.eu/prelex/ includes a complete history of every legislative document. It is most easily used if you have the COM document number of the initial draft legislation.
Find scholarly articles on EU law topics.
The commission library has a great database of books and articles on EU topics called ECLAS http://ec.europa.eu/eclas/F . This is not full-text, but can be used to find full-text articles. Another good source is the Legal Journals Index on Westlaw (LJI) which is an index of UK articles.