With so many avenues for searching and asking about terminology, it is important not to lose sight of a source that has been around since the early days: Yahoo! Groups. There are two such groups I belong two that I consult from time to time:
Legal Translators: Legal terminology in several languages including Spanish and English.
SpTranslators: A wealth of Spainish <> English terminology questions and answers with plenty of legal topics. Don't miss the late Bill Lokey's answers as they are superb!