Haven't stayed at the Thunderbird Inn, but it's very kitschy and gets good reviews on tripadvisor, so i'd go for it. It's very conveniently located to a couple of trolley companies, so that's a big plus. If you're looking for a B&B, try the Galloway house. I sooo want to stay there next trip.
I would reccommend doing a house tour. We did the Isiah Davenport house tour, but you can also do the Sorrell Weed, Juliette Gordon Lowe or the Owens Telfair house tour. I enjoyed the tour but wished we would have done the Owens Telfair house tour instead, it just looks so much grander and has a more distinguised past, architectually. You can do pub crawls and ghost tours but we never did becasue we stayed outside Savannah and I didn't want to get plastered alone, and since I'm a scardey cat, we didn't do either.

I would take the time to visit Bonaventure Cemetery, it's so peaceful there and some of the markers are very old and just beautiful.
Take time to walk the squares. DH and I did this and it took us about 2 hours but it was so relaxing and romantic. Plenty of good photo ops everywhere.
We had lunch (not dinner, less expensive) at Vic's on the River and it was absolutely delicious and such a beautiful atmosphere. We also love getting oysters and shrimp form one of the little hole in the wall restaurants on River Street. Lots of dining there. City Market has lots of shops and dining as well, we loved the pineapple gelato at Cafe Gelatohh and the homemade peanut butter cups at the savannah Candy kitchen to die for!!
I would try Tripadvisor for more reviews on restaurants and that sort of thing. There is lots to do in Savannah.
One great tip, if I do say so myself...go to
www.SavannahMenu.com and look into purchasing a savanah menu vIp discount card. you get discounts at many area restaurants and attractions. some are buy one entree get one 1/2 off, or a percentage off. A visitor's card, good for 30 days, is just $9.95. Ours paid for itself on 1 meal!!
Have a great time!!!