Welcome to the forums Snakeman!
All you have to do is daisy chain all of your fixtures together. It doesn't matter what order you do them in, just try to find the shortest path. If your DMX run is longer than 100ft it is advised to terminate the last fixture. You don't need a DMX branch or opti splitter. Just come out of you board into the first fixture, out of that fixture and into the next, etc. etc.
Also you may want to take of your e-mail address or seperate (robjan AT telus DOT net) it so you don't get any spam e-mail. Do it quickly? Mods if he can't get to it in time, do it for him!
Hope this helps!