Are you flying an airplane there or going on a smoker?
Lots of things to see up there. Get a copy of the Milepost (available on line, here:
http://www.themilepost.com/), whether you are flying or driving, it's a great resource of what to do and see along the road system.
If I were staying in Anchorage, I'd consider staying at the Long House Hotel, near Lake Hood, rather than at MRL. Merrill Field is pretty much an ugly downtown area with an airport. The Long House, on the other hand, is a block from Lake Hood, the biggest seaplane base on earth, and the center of a LOT of activity. Also a good aviation museum on Lake Hood, and a couple good restaurants/bars as well--try the Millenium Hotel's bar of an evening, with a great view of the action on LHD.
Seward is south of ANC, and will give you a glimpse of Prince William Sound. Silver salmon will be running in August if that's of interest, and it should be.....
Talkeetna, for an aerial tour of Mt. McKinley. K-2 Aviation or Hudson Air would be my first two choices, if not self flying. If self flying, stop and talk to Jay Hudson at Hudson's and get some advice on flying around the mtn.
Fairbanks is also a great place. An air camper park right on FAI International A/P if you fly in. A good riverboat tour--touristy, but I lived there for 20 years and rode the boat with friends any time we had visitors--enjoyed every trip.
Many, many other places to see and visit.
One of my favorite parts of the state is the Wrangells. You can drive to McCarthy, but it's a rough road (rental cars prohibited, but....) good airport, and fantastic country. VERY interesting history of the big copper mine there. Copper River will be Silver Salmon running then, probably, depending on how early/late you're there.
Give us more specifics--self flying, or commercial? How long? Interests?
MTV