Fantasy Fest is Oct. 21-30 this year. The last week of it is the busiest, and you should make reservations ASAP if you want to be in KW at that time. We used to stay at the Eden House, 1000 block of Fleming St.
Key West Hotels | Hotel in Old Town Key West | Eden House Hotel, Key West, Florida, 33040 It's very "old Keysish," has many different types of rooms and covered wraparound porches. Nice pool and gardens. A ten-minute walk to Duval, but it's quiet at night. Other people we know have stayed at Eaton House and The Banyan Resort.
There is a magazine that comes out every month that you can pick up free anywhere. It has a lot of the restaurant's menus listed. I love an outdoor casual place (under cover) on Duval called Willie T's
Willie T's Restaurant & Bar 525 Duval Best ever blackened grouper caesar salad.
BTW, the church Madelaine Aimee is talking about, St. Paul's Episcopal Church, 400 block of Duval, used to give free music concerts a noon every day but Sunday. I can't find anything about it on their web site, but if you want to get out of the heat, it's quite peaceful in there It's about an hour, but people come and go as they please. Their 9:30 "sung" Sunday service is awesome.