Amsterdam

Depending on your hotel location, you will either take the train or a bus into Amsterdam. Train if central , bus if Museum District. Train to Haarlem. All sorts of public transport available.

Hint: stay out of bike lanes as a pedestrian. This is very important.

Hotels within close proximity to where you disembark are further from Amsterdam’s sights. Sleep in the Jordaan neighborhood where you’ll be able to enjoy its surroundings. If you stay near the dock there will be no ambience and no place to go unless you do a lot of walking or arrange a driver.
You also asked if Haarlem is a good place to visit. I was disappointed with Haarlem since I felt there was little to do compared to Amsterdam.

Hint: stay out of bike lanes as a pedestrian. This is very important.

Couldn't agree more! Make sure you know what's going on around you at all times. Bikers ride unbelievably fast and wear no helmets.

If budget is not a concern, then likely you will stay either along one of the canal belts in central Amsterdam, or in the Museumplein area. Hotels in Amsterdam go fast and garner a premium price. There are a few hotels near Centraal Station and the Viking dock, the Doubletree by Hilton would be closest, but also a Movenpick, an Ibis, and a Renaissance. The dock itself is kind of isolated, but there are some trams and taxi might work as well.

From the airport, the easiest is to take a train to Amsterdam Centraal, then tram, Metro, taxi, or walk to your hotel. Because of pedestrian areas, one ways, congestion, walking is many times quicker.

For more budget options (Holiday Inn Express, a few others) the area around the Sloterdijk train station runs about a third to half what central Amsterdam is. Even staying in Haarlem or Leiden is not a bad option.

"is a side trip to Haarlem that a friend suggested worth the time? Many thanks,"

You are really only there for 2 full days. Your arrival day you'll probably be beat. The day you board your cruise you'll not want to do a day trip. I've stayed in Haarlem on a RS tour and I've visited there on a day trip. I'd not spend the time doing a day trip anywhere on your 2 days. There is so much to see and do in Amsterdam that you'll not get everything done.

Are you interested in Museums? Definitely the Rijksmuseum and the Van Gogh Museum. The Rijksmuseum has an excellent app so I recommend you download that to your phone before you leave home. Monitor their ticketing website to see if they are selling out. You'll need timed entry tickets to the VanGogh Museum and they are not sold onsite so you'll need to get them online ahead of time.

https://www.vangoghmuseum.nl/en/visit/tickets-and-ticket-prices

Are you interested in WWII? (I think I remember you are but not sure about your wife?) The Resistance Museum is very good. Most people try to visit the Anne Frank house. To me it's not a good venue if either of you have any claustrophobia - tight stairwell up to the attic and very crowded.

Have a great time!

There are a few different places that Viking docks in Amsterdam. Apparently we drew the short straw and we ended our cruise in some industrial area not at all close to city center. I don't think you get confirmation of the dock until right before the cruise. I would just stay in city center and take public transportation to the cruise dock, if possible. If not, use a taxi. Don't waste your days in Amsterdam at some isolated hotel.

You don't have time for Haarlem. If you want to do the Anne Frank house get tickets well in advance

We also did our air travel for our two Viking cruises. It worked well for us. It was cheaper and we could make our own plans for the time before and after the cruise. I'm assuming you end in Basel. There is a tram from where the ships dock to city center.

Amsterdam is very walkable. There are loads of hotel and restaurant recommendations on the Forum, so be sure to do some nosing around on here. My recommendations are:
1. Those Dam Boat Guys evening canal tour. Book ahead. This might be very fun to do on Halloween. The Guys have small boats (maybe 10 passengers?), and the tours are more fun than informative. If you do the last tour of the evening and are invited to continue on to the marina, do it! Our captain recommended a great local bar to visit for bitterballen and beer. You can also bring your own meal and drinks along. For this or other picnicking needs, I recommend Sterk Staaltje (https://www.sterkstaaltje.com). Very nice prepared foods, wine and snacks.
2. Rijstaffel. We enjoyed our meal at Sapurna, but there are other fine options.
3. Restaurant 't Zwaantje (The Swan), http://zwaantje-restaurant.nl/?lang=en. Excellent Dutch and French food, great atmosphere and even better service (it probably helped that my friend flirted with the owner). Reservation recommended. Very near Anne Frank House.
4. I really enjoyed visiting the Sam and Julia store, aka the Mouse Mansion. It's a great place to pick up souvenirs for grandkids. https://www.sam-julia.com/en-nl?oc=NL
5. Don't pack your days with activities. Just walking around is the best way to enjoy the city. This is probably true in a lot of cities, but Amsterdam's unique architecture and canals makes it especially true there.
Have a GREAT trip.

For the short amount of time you will be in Amsterdam, I don't think Haarlem offers that much over Amsterdam... unless you are a big Corrie Ten Boom fan and want to see her house. It was my favorite part of a one-week visit to Amsterdam last month. And I met a lady on the train whose only purpose for coming to Amsterdam was to see the Corrie Ten Boom House in Haarlem.

If you don't care about Corrie Ten Boom and really, really want to do a day trip, I would give a nod to Leiden over Haarlem.

If you want to visit the Corrie Ten Boom house you need to get tickets well in advance.

If you want to visit the Corrie Ten Boom house you need to get tickets
well in advance.

Yes, like make them now. Oct 31 has 12 slots left on 12:00 & 14:00 English tours. No tours Nov 1 and 2. The 10:00 English tour is sold out Nov 3 with 10 slots on 12:00 & 14:00 tours.