So far I like THW's idea about using several maps to illustrate the concept. One of the maps, like the one I posted, will show each island separately so that they can be named and such. Another map, like the one THW showed, will actually show the land masses as they would appear in the cluster. In this fashion I can show which ones overlap the others, etc. as well as which islands are attached to the other. In this version, like in the movie Avatar, some of the islands are connected.

In my narrative, some of the islands are chained together so that as they float they will stay in roughly the same area within the cluster. These islands float along a mana-line at a fairly slow rate of speed but they do move. I'm thinking that they only move a few feet an hour or something of that sort. Rather than using bridges between the islands (which I think would be risky because the islands do move about a bit and would probably crush a normal bridge), the people have explored gate technology (magical) to make micro-portals between the islands. It would allow them to move produce, materials and personnel across much easier. They probably - did- have bridges (flexible rope bridges) at one time but thankfully their ancestors figured out a magical solution.

This cluster of islands is, essentially, a floating kingdom.