I’m not sure if this has been submitted before, but little_details is a wonderful livejournal community full of resources for a writer who wants to get the facts straight.  An extensive tags list contains posts with information on everything from soporific sponges (used in the late middle ages as anesthesia, inducing unconsciousness) to the fate of farming on earth after an asteroid strike.

If you’ve exhausted Google or just aren’t sure how to go about researching further, the helpful members of this community will try their best to give you a hand.  Don’t have a Livejournal?  Don’t worry.  You can comment anonymously here and the mods will post your query for you.  Just make sure you follow the rules.