shadesong has recently made a series of interesting posts on poly, relationships, and boundaries. The purpose of the posts was mainly to make clear where she and her partners stand and how they operate, but there are many generalizable gems in there.
I particularly liked these two posts:
http://shadesong.livejournal.com/4411009.htmlhttp://shadesong.livejournal.com/4412337.html And, as others have pointed out, if nothing else, the terms "lion" and "cuckoo poly" are awesome and everyone should use them when needed. ;-)