What's a good website for asking questions about Jewish life and learning and getting crowd-sourced answers?
You might want to check out mi.yodeya.com, the Judaism site on the StackExchange network. They allow questions and even answers from anyone, but the community editing and voting process, along with the great crowd of people who tend to hand out there tends to result in excellent, well-sourced answers being posted fairly quickly for most questions.
Full disclosure: I founded mi.yodeya and am a member of Mi Yodeya.
There is an email list called Mail Jewish which discusses matters of this nature.
Send submissions/responses for mail.jewish to:
The archive site is http://www.ottmall.com/mj_ht_arch/
This is a listserv which has been in existence since the before the beginning of the internet (it goes back to the original Bell Labs days) and has dealt with all issues involving Judaism. It is a moderated list, so it is recommended that you look through the archives to see what types of things are discussed.
I would consider it as a crowd sourcing site and the archives are available as well. Mail Jewish Torah and Halacha Home Page Each volume is pointed to by Mail-Jewish Digest Hypertext Edition and Mail Jewish Volumes Archives
I have frequently seen such questions posted to general-purpose social media networks like Facebook, Twitter, and Reddit (particularly the Jewish corner thereof). These sites don't have the same controls for quality that Mi Yodeya does, but they can often draw large numbers of people to address a question, relatively quickly, with varying degrees of seriousness and usefulness.