Some of the most useful tax links:

Broward County Property Appraiser:
http://www.bcpa.net

Dade County Property Appraiser:
http://www.miamidade.gov/pa/property_search/asp/record.asp

Palm Beach County Property Appraiser:
http://www.co.palm-beach.fl.us/papa

Hillsborough County Property Appraiser:
http://www.hcpafl.org

Martin County Property Appraiser:
http://www.paoweb.martin.fl.us

Pinellas County Property Appraiser:
http://pao.co.pinellas.fl.us

Duval County Property Appraiser:
http://www.coj.net/departments/property+appraiser/default.htm

Orange County Property Appraiser:
http://www.ocpafl.org

Brevard County Property Appraiser:
http://www.brevardpropertyappraiser.com

Link to all county appraiser's offices:
http://sun6.dms.state.fl.us/dor/property/appraisers.html

More sites to come!