First trip to Venice

Our RS tour stayed at the Hotel Mercurio. It was a very nice hotel and was a short walk to St Mark's Square. I would stay there again.
http://www.hotelmercurio.com/en

You might also want to take a look at

https://www.tripadvisor.com.au/ShowForum-g187870-i57-Venice_Veneto.html

We like Dorsoduro as an area to stay, and it is close to both Ca' Rezzonico and Accademia galleries.

Try venere.com for hotels.

Or some blah blah that I wrote a couple of years ago:

http://www.fodors.com/community/europe/venice-april-2014-some-thoughts-.cfm

This is so vague. How long will you be staying, are you ending or beginning your trip in Venice, is that the only city you are visiting, how many are you, what is your budget, interests, etc.
What research have you done already?

Hello after.school! Venice is always a good idea and I am sure you will love it!

For a first timer I would definitely suggest visiting Piazza San Marco, as well as take a gondola ride along the Grand Canal to say the least. There is a very comprehensive top 10 list here of not-to-miss sights for first-timers in Venice: http://www.travelthingstodo.com/attractions-things-to-do-in-venice-italy/

Have a lovely trip!

Your budget would be good to know. My budget is generally around 75-80 euro a night and we have a nice spot we've stayed at 3 times. But if your budget is 150 a night, you can stay in a much nicer place.

But I do recommend staying in Venice proper and not Mestre (unless your budget is really low for accoms).

After School,

You don't provide a whole lot of detail but I'll though my advice out in case if fits your particular needs.

On a 5 day visit last fall, we stayed in 2 bed/2 bath apartment overlooking Rio Marin. The apartment was close enough to the train station to be convenient but far enough off the tourist route to be quiet and tranquil. Best of all, it was right above a very nice grocery store.

The beauty of apartments is they give you space to spread out and relax after (or during) hectic days of sightseeing. We loved being able to cook our own breakfast and enjoy several cups of espresso before heading out in the morning.

There are a multitude of holiday apartment web sites and I found that most rentals are listed on most (if not all) of them. I'm sure you'll be able to find an apartment that ticks all the boxes while staying within your budget.

By the way, I rented three apartments in Italy last October (Venice, Florence and Rome) and each rental experience was outstanding. The level of service was outstanding with each and I had not difficulties whatsoever.

My family and I stayed at Hotel Tivoli near Frari Church. This is a safe choice for "budget" travel. Has stairs and no elevator. A/C at night time - close your windows to avoid mosquitoes at night. Has breakfast. Clean room. No decor to speak of. Near San Rocco complex, Frari Church, some reasonable and decent restaurants. I would stay here again.