That sounds like a great trip.
While in Homer you should definitely check out Homer Brewing Company (say hello to Karen and Steve for me) and the Ring of Fire Meadery.
On the way to Homer there is the Kenai River Brewing Company and St. Eilas Brewing Company in Soldonta and Kassik's Kenai Brew Stop in Kenai. All three are well worth stopping at.
I have a Alaska brewery webpage at: http://www.mosquitobytes.com/Den/Beer/Breweries/Breweries.html
. This should give you an idea where the various breweries are. I've included some contact information a link to the official brewery webpages where they exist. Keep in mind some of the offical webpages are under construction and do not include a whole lot of information.
While in Seward I would recommend taking one of the Kenai Fijords tours. I've gone six times and it is a great trip. You often seen glacial calfing and quite a bit of wildlife including humpback whales and orca. I've been on that trip six times and will likely go again.
Anchorage is the Mecca of brewing in Alaska.
Midnight Sun Brewing was already mentioned. Their beers are quite nice.
Glacier Brewhouse is a very nice brewpub. It is kind of expensive but has very good beer and very good food. They have as my wife puts it bread pudding "to die for".
Having said that, whenever we are in Anchorage my wife and I always go to Moose's Tooth. They have wonderful pizza and very good beer. Although they made their own beer the brewing equipment is not on premises so techinically they are not a brewpub. At any rate, they are always busy regardless of the time. If you go you will have to wait at least 5-10 minutes. However, it is worth the wait.
Somebody mentioned Humpy's. They have an impressive line up of beers. However, they tend to attract and younger crowd. Being an old fart I prefer the mellower Café Amsterdam http://www.cafe-amsterdam.com/am/
In terms of things to do in the Anchorage area I highly recommend going to the Alaska Native Heritage Center Museum http://www.alaskanative.net/en/home/
My wife and I also really like the Alaska Zoo http://www.alaskazoo.org
. It is a small zoo but it is a really nice walk and a great place to "decompress". The zoo features Alaskan wildlife (e.g. Polar Bears, Musk Ox, Moose, etc.) and other cold weather animals (e.g. Yaks, Snow Leopards, Amur Tigers etc.).
Beer culture is alive and well in Alaska. In fact, the Arkose Brewery in Palmer is having their grand opening today (October 11).
I hope you have a wonderful time visiting Alaska and drinking your way across our great state!
Have a most excellent trip!!