Where's the best place online to quickly hear French prouncations of words?

Google Translate has a “read aloud” feature. The French computer voice is pretty decent.
Just enter your text into the box and click “listen”.

@Fyrius beat me to it
I used to use translation2.paralink.com (still do, especially for italian), which includes a handy internet ladyface thing, too.

First of all you should try out Forvo and RhinoSpike. These you can hear recordings of words, phrases, etc., in many foreign languages. These are crowd sourced, almost like social media, so the members participate in the pronunciations. Forvo only does individual or compound words whereas RhinoSpike can be sentences, phrases, clauses, paragraphs and even poetry. Another you might look for is Oddcast (http://www.oddcast.com/home/demos/tts/tts_example.php?sitepal). Oddcast is not for language learning but I do think this is much better on the languages that it has than Google Translate.