There are two ongoing posts on the Alaska/Canada forum of this site.
1. There's a 'Clicky' at the very top which will give you lots of helpful information on what to take and what to do.
2. There's a post of those going this summer in 2015. They'll be posting all summer as they travel. This yearly post has been up and running previously.
Alaska is a easy trip to make. The only different part from traveling in the lower 48 is the distance. However, don't think of it that way. Just break it up a day at a time and it won't seem so far.
Roads are good. Don't listen to the horror stories out there. These come from folks who have never driven it or have driven it 20-30 years ago and the story is embellished time after time. You won't be interstate driving. You'll be going slow and you should for many reasons - some road construction (as happens also in the lower 48) frost heaves (usually well marked) and if you go slow you'll see more critters.
Border crossing are easy - IF you abide by rules. Campgrounds are adequate - not resorts. Boondocking is awesome and plentiful. Fuel is available but it's worth it to always run on the top 1/2 of your tank. It's not the time to shop for prices. When you see it; get it.
The trip is expensive but for many, it's a once in a lifetime kind of thing. It's an adventure not to be missed.