I did 3 trips with work to Alaska in 2012 around the same time of year with the longest being 3 weeks.
I didn't find the mosquitos a problem, but then I was mostly in the town centres or in a car and not hiking through the wilderness.
The summer tourist season only lasts a few months, so many of the businesses are geared towards making enough money during this period to cover the whole year, so be prepared for high prices! My first trip at the end of April, the hire car was about $30/day and the hotel room was about $100/night (Marriott in Anchorage). However in June/July, the hire car price jumped to over $150/day and one of the few hotel rooms available in Anchorage city centre was over $300/night (Captain Cook). If hiring a car, then most hotels have valet parking, but it's possible to park a few blocks away for free. Parkling in the city centre can be tricky at peak times, but if you are prepared to walk 10 - 15 minutes into the city centre, then it's generally not a problem as many tourists are pensioners who don't want to walk more than 100m. Lots of coach tours stay at the city centre hotels, so expect breakfast to be busy between about 7:30am and 9am
Working during the week, we only had the weekends to explore. Seward was a one day trip there and back from Anchorage. Some great scenery en-route, but not as impressive as heading north where we went up to view a Glacier. However, after you have been there a few weeks, driving for hours with epic snow covered mountain vistas does become a bit tedious.
Eating out can be pricy (many things are imported) so budget around $30 - $50 per person for dinner with a beer or two. The menus will be dominated by salmon and steak, with few chicken dishes for some reason. There are plenty of local beers available which are mostly excellent.
There was one Indian curry house in Anchorage when I was there (you need a break from salmon and steak after a few weeks), but avoid it despite the temptation - it was the worst Indian meal ever. Best steak in town was at Club Paris. Decor is a bit dated, but food was superb. Alaska is also famous for other seafood such as crabs, but these are generally sold by the lb, and again are very expesnive during tourist season. Simon and Seafort's overlooking the inlet was a great restaurant with great service, but you do have to book a day or two in advance. Their halibut dishes were superb! Best breakfast (and much cheaper than the hotel breakfasts) was the Snow City Cafe just around the corner. They often have queues of people waiting outside before opening time in the morning (7am), and even then you might have to wait 20 - 30 minutes for a table. The Crow's Nest on the top floor of the Captain Cook hotel is excellent, but expensive. Great views though, and ideal for a special occasion meal. Having said that, there is a lively pub downstairs (Fletchers I think it was called) in the hotel which serves decent pub style food. You don't need to be a resident to eat there.
If you forget anything photography wise, or need a new filter etc, then there was a good camera shop (Stewart's) in downtown Anchorage that I visited a few times. They have a reasonable selection of DSLRs and lenses, but lots of other accessories like tripods, filters, bags etc. They even did a sensor clean for me ($50) after I got a few dust spots having changed lenses on a windy day.
I was lucky and got a trip on a chartered flight up north to Deadhorse (nothing to see there and it's dead flat!), which meant flying over the Denali mountain range. There are plenty of local air tours available that fly over the mountains and glaciers, and many are in sea boats so you can land on the water. Would highly recommend taking one of these trips. Even if it is expensive, you are likely to be there for a once in a lifetime trip, and won't get the chance once you are on the plane home!
If you don't fancy the long journey to get there via London to Seattle to Anchorage, then there are a few direct flights on Condor airways who fly from Frankfurt:
https://www.condor.com/us/flights/germany/frankfurt-int/from-anchorage/index.jsp
If you are taking your camera equipment in your hold baggage, then make sure you get one with TSL approved locks, otherwise customs have a tendency to force open your case if you leave it locked. When departing Anchorage, I was advised each time to leave my case unlocked, despite having 2 connecting flights back to Scotland... I did, and everything was fine, but I did have the works insurance covering my stuff. My case was opened once on the way there (the one time I put the camera into the hold baggage).
The aviation museum on the outskirts of Anchorage (where the sea planes arrive and depart) was interesting and was a good way to spend an afternoon and wasn't too expensive either.
Never got the chance to head down to Juneau as it was just a bit too far for a day trip there and back from Anchorage.
