The threats are biggest to:

• Miami
• Florida Keys
• Everglades

Threats:

• Heavy population along the coastlines
• Increasingly damaging flooding
  • needed reform in the National Flood Insurance Program [2]
• Saltwater intrusion into limestone aquifers

Timeline:

• The short-term effects won't be the sea slowly filling in spaces. Rather, it will be increased periodic flooding from storm surges associated with hurricanes and king tides [2]
• the timeline of actual sea level rise

Good articles, targeted for a lay audience:

• [Feb 2015] Climate Change Economics: Treading Water National Geographic
• [Sep 2014] Water's Edge: The crisis of rising sea levels Associated Press
• [Jun 2013] Why the City of Miami is Doomed to Drown Rolling Stone

Drinking water

• South Florida Water Management District
• Biscayne Aquifer
• Southeast Florida Regional Climate Change Compact
• rising sea water pushes fresh water aquifers away from the coast [2] [3]