It's so tempting to keep build quick and sloppy, but I know I need to be more diligent with testing and documenting.
I'm setting a relatively low target number of users to acquire just to make sure this idea has a chance, before bringing on a developer.
Very broad question, but how does one find an experienced developer? I live in New York, but have zero tech connections.
That's normal when you're starting out. The only reason more experienced developers do not give into this impulse is because they've learned of the consequences through painful experience.
I would recommend looking at the people who contribute to Rails, Ruby and related projects on Github. The core developers will be far too expensive but people who throw some code out every so often (assuming that their pull requests are usually accepted and nobody is shouting at them in the comments) will likely know their stuff and may have reasonable prices.
IRC channels on Freenode such as #ruby and #rubyonrails will likely prove useful too. Look out for people who answer a lot of questions (and get them right). One strategy is to try to design a solution for a feature by yourself, then summarise the design (i.e. show the relevant code snippets) in a Github Gist or pastebin page and ask for feedback. If there are any glaring faults or simply better ways to achieve the result then they will be pointed out to you.
Actually, beautiful women are hardly rare. But it's the qualifier that's important: "models I can date??"
Good developers might be rare, but they're not hard to find. They are, however, hard to woo. You know the drill on how to woo them, it's just inconvenient/hard/expensive. But at least it's pretty well laid out.