Welcome to this challenging, yet rewarding growing environment of Southeast Alaska. Many gardeners from elsewhere are surprised by what we can easily grow, but also what is required to grow easily in other places (ie Tomatoes!)
The general idea is to find varieties that have the shortest maturation rates and enjoy cool, wet conditions. Root vegetables generally do well here as do all the brassica family (kale, etc.). Our first and last average frost dates hover around mid May and mid September. Each growing season is highly variable up here so finding and using some known best practices is very important for a successful harvest (ie raised beds, liming, covering certain crops under hoops, etc.) .
The best idea is for you to take a class (I am offering one at the Cooperative Extension in Juneau this Spring), connect with gardeners (look up the Juneau Garden Club (JGC) and Southeast Master Gardener Association), join a community garden, access our Extension publications and check out the book Gardening in Southeast Alaska - by the JGC.
This is in the process of being updated, but all are proven varieties.
The good news is that we can have excellent harvests in Juneau, so "don't get frustrated, get help!" Our grdening community is extremely generous and love to share. Oh yeah, don't forget to keep your eye out for the big Garden Sale (Safeway parking lot) on Mother's Day weekend and the Garden Tour (by MG Association).
UAF Extension Agent Juneau