The only issue I have is #4 which I bought mostly for the J. Scott Campbell varient cover. Like yourself, I thought it looked pretty cool and of course Michael Turner's art was good as always, but because I hadn't read the previous issues I was pretty lost.
Fortunately I've managed to locate a couple of sites that were helpful:
This is Turner's official site. It contains in-depth character bios, A list of all the issues with brief plot descriptions, a preview and plot description of Issue #5 and even has a store that sells most of the back issues.
The on-line encyclopedia. This gives a general overview of all the story arcs and brief character bios. It also has links to the official site and a fan site. Probably not as useful as the first one, but might be worth a look.
Hope this helps.