Ah, this I totally get. I think this might be a good function for the welcome thread -- you could just leave a comment saying "hi, I'm thinking about writing something about X -- is there anything I ought to be reading first?"

I imagine that some of this task will be handled by the wiki or the tags assigned to each post.

That being said, I have little problem with someone talking about a topic that was broached seventy times previously as long as it either adds a new perspective or is a decent summary or launching point for people not there during the past discussions.

That being said, having "little problem with" may mean I will not read it because I consider the topic saturated.