Your call to action button is hidden in the bottom right, well below the fold. I'd recommend hiding the main form completely on the landing page and replacing it with that. Use A/B testing to see for sure, but in general, 1 easy button = conversions.
The layout and design flow look great, though I'd drop the 'PlaceIt Screenshot' byline with something else, even though they're super useful ;). Ideally if you can get a video in there, that'd be excellent, but I know that gets pricey...
I'm also in the 1st webapp startup boat, and as a fellow Canadian, I wish you best of luck! You can check out my startup at http://wwww.tryringo.com
Good luck!
Ringo looks cool. Interesting that you put the Terms and Privacy in the header navigation. I don't think I have seen that before. Any reason in particular why?
The back end I am using Yii only because I played with PHP years and years ago. As for as PHP goes, Yii has been a joy to work with, but I am definitely weening myself off of PHP for my next project(s). I use MySQL as the db, and hosting is on AWS (SES, EC2, ELB, S3, and so on).
As for front end. I am using backbone w/ marionette. Very awesome combination but I think I'll move away from backbone going forward. Analytics I use segment.io, payments I'm using Stripe Connect, and Bootstrap as the UI toolkit. I think that's it.
There is a trust system which encourages users to get more verified and to participate more in the community, which further builds trust. I'd like to continue to add trust cues, such as integration with trustcloud and other services eventually.
tl;dr: trust is important on Rentything and not so much on craigslist.