Probably most of you have used Google Translate. Though it is far from perfect, you might have gotten some useful information out of the experience. Some phrases are nearly perfect, and if you have lists of countries or diseases, the results can be startlingly accurate. But then again, don't expect Google Translate to churn out even a respectable rough draft translation of your contracts and divorce decree. You will still need a human being to do that.
I have broken down these resources into two types: context based and dictionaries. Dictionaries are good for learning what a term means; context sites are good for learning how a term is or could be used.
Here are some more resources:
1. Word Magic Detailed online dictionary with Spanish synonyms. Excellent for general terminology. Somewhat vague with legal terminology. You can buy separate, thematic dictionaries for desktop computer, but there is no real need to.
2. Linguee Multilingual site that gives you context taken from vetted documents instead of a plain definition. Heavy on EU material.
3. Reverso This site acts as both a dictionary (Collins) and translations of the word or phrase you enter in context.
4. Wordreference Dictionary Similar to Reverso, but with more options. You have a Wordreference dictionary after entering the term in the search box, but after that you can decide whether to listen to the word in Spanish, view the Collins Dictionary definition, or view the Word Magic Reverse Dictionary. Note that you can see the entries before and after the term you searched, much like a paper dictionary.
5. DeepL Translator Like Google Translate. Try them both and see which one works for you.
6. MyMemory is context based: it gives you both a machine translation and translation memory. Even if your exact search is not returned, you can still see similar phrases.
7. IATE I have found this resource to be quite reliable. You can find a huge number of terms here which are taken from official European sources.
Of course there are countless more bilingual resources. If you find one that is useful, let me know!