Bem-vindos ao Brasil!
Florianopolis is really needing some attention. There are only very few hostels and I haven't heard good things about them.
I just searched HostelWorld and there are only 17 results!!!!! This is ridiculous, Florianopolis and the region (Camboriu, Itajai, etc) are huge beach destinations with tons of things to do and amazing nature (see for yourself Beaches in Floripa ).
In summer season (November-March) you will get tons of tourists not only from abroad but also from Northeast Brazil.