Have fished Alaskan waters for 25 years and have enjoyed my share of five species of salmon and a variety of pelagic fish (halibut, yellow eye, ling cod, black cod).
Preparation for your salmon fishing adventure will depend on whether you will take the challenge of a self-guided fishing–a skiff and outboard motor–with your own gear.
Charter boat fishing will provide everything–just prepare for weather conditions.

if you wanted to get your foot in the door, i would suggest trying to get a job at the processing plants up there.

http://www.unisea.com
http://www.westwardsefoods.com

those are two major companies up there that process pollock in the summer and winter. the summer season for this year is just getting started so they are probably not hiring for that. they are also based out of seattle, so it might be worth calling em up. they dont pay great but you do work 12 hours a day 7 days a week, they provide food, housing, laundry and maid service. you dont have to do anything but work ( and work hard). you can make a nice chunk of change if you do a season with em, and you may have a chance to meet the crews who work on the boat.

also do not go up there without a job. it is about 1400 dollars for the cheapest round trip flight and the hotel is 150 a night, meals are very expensive, weather in the winter is mild by alaska standards, but they can get very stormy up there. the summer is the same as a seattle winter.

i worked up there back in 2001, i made decent money. also if you do get on a crab boat dont think you will make anything near what they say the crew makes on tv.