Luggage and bags:
The weather changes quickly here so expect anything!!!
Clothing/Shoes/Weather Gear: Raincoat, windbreaker, sweatshirt, fleece, T-shirts
Toiletries and Medical Supplies: No hospital in Skagway or pharmacy...bring your meds!
Photo Equipment: Digital camera and leave lotsa room for zillions of pics
Camping/Beach/Outdoor Gear: good hiking boots, great trails nearby!
Bring Layers. I packed a rain/weather proof jacket, a fleece jacket and then various short and long sleeve shirts. That way I could start off heavy and gradually peel off clothes if the weather happened to be nice that day. I would also suggest weather proof walking shoes. In late spring we still ran into some snow at high elevations.
Photo Equipment: Digital Cameras are always my first pick, however sometimes in trying to capture photos of wildlife the animals don't wait for the digital delay. So it might be helpful to also carry a good old fashioned camera that uses real film!
Miscellaneous: Take binnoculars! We traveled with our 1 year old son and a back pack was the best way to carry him around. Strollers don't always work in some of the towns (not great sidewalks) and a back pack allows you to virtually go anywhere.
Luggage and bags:
Maximum of two per person both of which will pass the carry-on test. Pack for half the trip. Do laundry if you need to, or better don't take anything you wouldn't wear twice and could combine to make a new outfit. Alaska is most definitely not a fashion show.
Clothing/Shoes/Weather Gear: Layers Layers Layers
Good hiking boots or very comfortable walking shoes with good soles and a waterproof shell are essential. You can even get by without a coat except in the winter. I didn't take a coat and I still found myself shedding layers, even after the first sunstantial fall cold snap and snow on the surrounding mountains. Take a fleece sweatshirt and long underwear and you are ready for anything nature has to offer from May to September.
Toiletries and Medical Supplies: (One Dramamine non-drowsy) makes you a little sleepy, but not hung over.
Photo Equipment: A zoom is really nice for wildlife shots. Binoculars are very useful.