After taking massive shipping loses (400+ points worth), I decided to restart the Guadacanal scenario from the first turn having, as they say, "learned from my mistakes" (and some were pretty "dumb"). I'm now up through about turn 7 again. The logistics issues even in this scenario are something else. As Canoerebel said, it's important to figure out where your next steps will "flow." One thing I did was to get my support units "flowing" towards Guadacanal even before Lunga and Tulagi were secured, and even moved the Americal Div. right away to Tassafronga (now captured).
Regarding Port Moresby, I'm trying to flow supplies (and units) there in a more organized fashion, using Cairns as my staging area (I discovered that Cooktown isn't as good because you can't go directly from there to Port Moresby). Port Moresby became a shipping "graveyard" for me, and I'm trying to avoid it this time arround. I'm also using my B-17/B-24 forces more judiciously to suppress the bases at Buna, Lae and Rabaul.
One question I've got relates some of the ship types like SC, PG, AV, AD, etc., that appear to be for transport, and especially what they're used for. I know what AKs, APs, AOs, TKs, APDs, etc., are used for, but what about these others. For example, I know SC stands for "sub chaser" but what exactly is it's role in this game?