I tow my Bigfoot
between California and Alaska twice a year, up in the winter/spring, down in the early fall
. It's an amazing trip.
I can't emphasize enough that your trailer and tow vehicle need to be in ultra reliable mechanical condition. What holds up on the Interstates in the lower-48 can easily be pushed beyond their limits on the Alcan - and there is little help in the far northern stretches.
I bring my two dogs and rbryan's advice is spot-on. If you have any other specific questions, post away I'll try to provide some useful information.