I'd recommend registering on
Hackernews and asking your questions on the "ask" page.
It's a forum where a lot of startup founders, developers, marketers, and other people familiar with startups and funding hang out and discuss.
Update: And if you have a demo site, you can put it up on their "show" page and get very useful - and usually brutally honest - opinions from people. It's a good way to
test market demand.