First off gheenoe’s are harder to pole than a regular flats skiff as you’ve found out already. I used to have a gheenoe classic, a little wider than Andrew’s boat but pretty similar design.
As far as an online article it doesn’t get any better than this one by Tom Mitzlaff.
I poled my boat for the first time this past weekend, It took a little while to get use to, but once I did, it was fairly easy.
FYI- I did not order a pole in time for my trip, so I used an aluminum pool cleaning pole, you can get a 12′ one at walmart for $20, I got a 16′ at a pool supply store for $30. It ended up working really great, and it’s pretty light, all you need to do is plug the end so mud will not fill it up.