Start looking for lodging now. It's always scarce and always expensive.
Weather changes quickly, Juneau has its own weather, leave the bay and it can be completely different.
Do NOT trust the Chilton EFIS as your only navigation. It's good to have but it freezes up without indication. Froze on me several times and it probably killed a friend of mine.
As said above, the wind shear at Haines is no lie. Be ready, especially if you're heavy.
Hoonah.... oh Hoonah. Don't be afraid to follow the water to the marina if you're really heavy.
You'll carry so much interesting cargo. Fish, boats and motors, groceries, seaweed, bear hides, and so on.
Learn your reporting points, and never let the passengers distract you from listening to other pilots reporting their position. Almost cost me a mid air. (carelessness on my part)
Water hovers around 40 degrees F. That gives you 15-30 minutes assuming you're in good shape. Something to consider if you ever have to ditch. (I only know of one incident)
Hell of an area to fly in. Enjoy the Glaciers.