Looking to spend a weekend in Newport with my wife. Looking for advice with regards to time of year (we are thinking of this Oct-Nov or next June). Not looking to break the bank at absurdly priced hotels but also not looking to be squeezed in a small B&B room. Willing to use car to drive to locations Love lobsters and sitting at pier relaxing and drinking. Will want to tour mansions and make river walk.

What else would be exiting to participate in?
Are 3 nights and 2 days ok.
Like to eat at non commercial-tourist lunch - dinner places.
Will not dress up-need to be casual.
We live in Princeton so the travel is somewhere around 5 hours.

About the timing. I believe that "off season" when hotel and inn rates drop dramatically starts November 1st and goes to May. Lower rates are the main advantage, but in November,at least, some of the mansions are closed for the season. Breakers and a couple more are open year round. Weather then is more iffy, but I went one early November weekend a couple years ago and the temperature topped 70, so you never know.
June will be great, but prices will already be at their higher levels anytime after Memorial Day
(Did you mean 3 nights 2 days, or 3 days 2 nights, or 3 nights 3 days? 2 days to tour around will get you started, but could be a little rushed, especially if you go during summer)

(By the way, did you realize that you tagged this question with several states but not with Rhode Island?)

That's why I need advice on Newport. I am not that bright.

Is there any way I can retag this for R. I?

I would recommend a tour of the Naval War College (if possible), and the family home of Jackie Bouvier Kennedy.
The beach "cottages" (what we would call the mansions!) are so much fun - nyer makes a good point about checking to make sure you go when sights you might want to see are open.

What you do really will depend on the time of the year and the weather. As I mentioned, off season makes things much cheaper and much less busy, but you may hit cold weather or miss seeing a specific site you have in mind.
On a non busy weekend day, you'd be able to see The Breakers (a must) and you could add another site (Touro Synagogue? Tennis Museum? Museum of Yachting at Fort Henry and the Ten mile drive to get there), a nice lunch and/or dinner, some down time, and you have a full day.
Another day, if the weather is good, walk part of the Cliff Walk (park free near the stairs access point, next to Salve Regina University), another mansion (Doris Duke's Rough Point if it's still open for the season, Astor's Beechwood), shopping, eating, hanging out--sounds good to me!
Places to eat: The places near Banister's wharf have nice views, but are the most touristy too. Go further down Thames street and the mood changes a lot. In that area, I like Zelda's for lunch, brunch or dinner. Mama Luisa's Italian is modest amd delicious. For Breakfast, Corner Cafe at the other end of town was casual, filled with locals, and great. Nearby are the dinner spots, the funky Salvation Cafe and Tucker's Bistro, Both are very local (but very different from each other--look at their menus online)

I would like to second Zelda's. If you cant stay at Castle Hill bec. of their prices (who knows, could be doable off season) eat there anyway. Great food and view.

You have all been most helpful.. Will probably wait till June. And will spend time in decision making your input.

For mansions, I recommend Breakers and Rosecliff, 2 of my favorites.

Also, Jackie Kennedy's summer home, Hammersmith Farm.

My favorite restaurant in Newport is Puerinis on Memorial Blvd.

We are going up the first weekend this October and I just got the Viking Hotel for $70 on Priceline. You may want to give Priceline a try if you wan to save some money. They have three 3 1/2 star hotels in Newport and they are all in a convenient location.

Am reviving this older thread just to let folks know that Hammersmith Farm (the childhood home and summer home of Jackie Kennedy) is no longer open to the public. It can be seen at a distance from the road, but that's it.