I have worked about an year on my startup website and I found that I need co-founder that would be able to sell ice to the eskimo nation online (online: marketing, sale and PR. But more of manager than technical skill).
I realized that the technical side of advertising online is not that difficult but that part is only 10% of the whole picture.
I'm located not far from New York City, so if you know about any events or places I would very gratefully. Also I have no problem driving up to Boston or surrounding states.
I know about startuply.com but I didn't find it helpful. I would rather meet people in person. I'm not sales guy but I think I have pretty good luck pitching my startup to people thus far.
I recommend networking, attending events. Meet people for real, you'll forge much stronger relationships than online.
But it will take 6 months for you to find someone, be realistic.
"Try a recent MBA marketing grad"
That's frankly my last choice. I want someone who's been in the trenches. If you know of an MBA program that emphasizes the psychology of marketing I'm truly quite interested.
Secondly, if you don't have those sales/marketing skills (they're not the same...do you need a strategist or a salesperson?) I would be skeptical you could hire someone to do that. I would consider a truly proven marketing coach to help you find the right person.
Finding them is pretty easy but finding the right one is difficult.
This is one of my hardest to solve issues as well, I am trying to set it up so they find me.
More helpfully to you though, we have had success looking at other vendors to the target industry/market and finding them through trade show meetings. We have also found a good head hunter (rather than a standard recruiter) who knows us and our profile and is really good at matching the right person.
If you don't have a huge cashflow there are companies who train promising sales people up and place them with you for a while.
Or go to linked in and have a look through there for the right profile person or possibly have a look on Stackoverflow Careers as an outside bet.
In the meantime, read some Al Ries, Seth Godin, and Guy Kawasaki. Good luck.
Are you affiliated with a college at all? That's a good place to meet people.
You can also find a lot of good people at conferences, and of course online.