You can use Thomas Cook to get from Germany to Alaska by air directly. When I went to Alaska I travelled off season and I took Delta Air Lines or the boat from Bellingham (Alaska Marine Highway). You reach Bellingham vom Seattle by train (Amtrak) or by bus (Greyhound). Alaskapass gives you a lot of opportunities to get there by boat or bus and to travel around in Alaska. When I took this trip it was really cheap but it's now much more expensive.
Another way to get to Alaska is by train via Vancouver and Prince Rupert or via Vancouver Island by boat / bus / boat to Prince Rupert.
On the way from Anchorage to Fairbank I recommend an intermediate stop at Denali National Park.
Don't miss Museum and botanical Garden of the University of Alaska in Fairbanks.