Finding the right investor is like finding a partner. It takes time, there are such dating websites and groups, typically angel investors are what you are looking for.
Build up a profile of the type of people you need (it may be more than one). List out the skills and attributes you lack, along with the personality traits that will suit you in a working relationship. Work out what you are going to offer them ... 50/50? probably not, but it needs to be thought out properly as to how much, what for and why.
STart talking, most major cities have events, over here in Melbourne we have FundingConnect, Tech23 and a host of MeetUp.com groups that you can go along to (though the Meetup groups are more miss than hit in my expereience).
Publish on your blog / website and twitter that you are "seeking a match with ..." and start the conversation off.
... If your idea is going to expire then I would say you need to build a "hungry" team first up, get people who are willing to work for the chance to make it big, and then get an investor who is ready to back you, bet big and help given the team is in place to nail it.