Need help planning 1st trip to Europe with 12 and 9 yr old 2018

We would like to go to Italy for two weeks in the summer of 2018. We
are a family of four-with 2 kids, 12 and 9. Have never been to Europe,
but have picked Italy for our first trip.

I'm confused. I thought you had already been to Italy several times before.

https://community.ricksteves.com/travel-forum/tours/suggestions-for-apartment-near-florence-before-sicily-tour-2018

My husband and I have several times. I am trying to help out our son and his family as they have never been.

I would start in Venice and fly home from Rome. If you have 14 nights, I would split them as Venice (3), Florence (4 with a day trip to Siena), Monterosso (2) and Rome (5) in that order. You can take trains between locations. I recommend vrbo or homeaway for apartment rentals. This will give you separate bedrooms for the kids and an extra bath if you choose it, plus a kitchen. Depending on travel dates, you should be able to find reasonable apartments within walking distance of everything in each city.

Definitely get the kids involved in planning what will be visited. If the adults do all the planning and the kids are "just along for the ride" they might not be happy campers. Unhappy kids for two straight weeks in the summer in Italy is not a pretty thought.

Fly round trip to Rome.

Arrive in Rome & train straight to Florence (5N)
Visit Lucca, Pisa, Siena

Then by train to Sorrento (5N)
Visit Capri, Positano, Pompeii, Naples

Finish in Rome (4N)

We are a family of 4 with similarly aged kids and have been to Italy numerous times.

First, I would urge travel in June, rather than July or August. Kids in Europe typically get out of school in July and August, so everything is packed in those months. We have been everywhere on your list and my kids really love Venice, Cinque Terre and Lucca. Florence is ok for the parents, but really a bore for kids. Rome holds the attention a little longer, but not much longer. I would definitely spend 3-4 days in Venice, especially if it is your arrival city, primarily to counter jetlag. A day trip to Verona (where we just spent a week) would be fun. I would also highly recommend a week in a town like Lucca. From Lucca with the train you can visit Pisa, Florence, Cinque Terre very easily. Lucca itself is a gem and so family friendly. We stayed in great apartments with 2Italia. I dream about that terrace. I would then move on to Rome for the rest of the time and fly home from there. A note on accommodation, which you have already hinted at - finding hotel rooms for a family of 4 will be a challenge. Either take two rooms or stay in apartments.

Those are great suggestions! Thanks so much. Making sure the kids are involved in the planning will also help in learning about the cities traveled to. Loved the idea of a town to stay in and then traveling to other towns from there. No suitcases to hassle with! Wasn't sure about Venice for kids, but definitely will look into that idea. Again, thank you all.

Our family of four was very comfortable in Florence in the Green Room at Casa edi Tintori, close to the river and an easy walk to the duomo.

http://www.casadeitintori.it/en/

The room is nicely set up to afford a bit of separation between two sleeping areas ( the headboard of the bed provides a half-wall between the lower and upper areas). The bathroom is quite large by Italian standards.

I will "second" Emily's suggestion to go in June rather than later in the summer. And the thought of skipping Florence and Rome in favor of Lucca and Venice with children that age.

In Lucca ( same trip with our two daughters) we really enjoyed this 2- bedroom apartment:

http://www.casaolivieri.it/location.html

I believe it has a 3- night minimum.

I am sure you can get lots of recommendations for a Venice apartment if you decide on that as well.