I spent last summer in Alaska and may go back for a portion of next summer.
Definitely, Church's book as Tina suggested.
We boondocked most of the time.
If you go to
www.gasbuddy.com, you can follow current fuel prices to give you an idea.
Extra expenses depend on what you want to see and do. You can usually find those costs online as well.
Verizon Mi-Fi generally doesn't work in Alaska - it is an AT&T state.
Have fun planning!!