Branching out into a new research area I'd like to move out of my comfort zone and do research on a topic that I know very little about, but is closely related to topics I have published papers in. Specifically, I have an idea from some of my previous papers that I think can be applied to this new area.

The trouble is, I don't know what the community in this new research area considers interesting. The literature in this new topic is vast, and I don't know anybody who works in this topic.

I have gone to Mathscinet and tried tracking down what seem to be the important papers in the area, and I have cold-emailed people whom I think are the experts in the field for help finding references related to my idea (I have gotten one response, which was very helpful). 

Nevertheless, I still feel my understanding of this topic is very shallow. I think my idea, if it works, would be interesting to people in this field, but I am not confident in my ability to connect it to previous work and to explain to the community why they should find it interesting. (I am not concerned with the possibility that my idea has been worked out before, I have reasons to think this is very unlikely)

This is the first time I am venturing this far away from the topics in my PhD thesis, so I am not sure if there is more I can do to familiarize myself with this new field. What do the rest of you do when you are preparing to do work in a new, unfamiliar research topic?
Be sure you read the relevant articles you can find so that you know what has already been done. Then go to the relevant conferences and see if you can talk one of the senior people into giving you 15 minutes for a discussion of your ideas over a cup of coffee -- and if that turns out to be productive, see if they are interested in collaborating in a paper. You will likely do the majority of the work for the paper, but the senior co-author will make sure you stay on the right track, and point you at other papers that you may have missed by yourself. He or she may also introduce you to other researchers in the field who have thought about connections between fields such as the one you have in mind.