Where you can fly your UAS depends on lots of things. Commercial users have different rules than recreational users. Right now you will need to consult a map, but be aware that this is all a work in progress. And, there remains some airspace over installations that are sensitive but not yet on maps.
The FAA has a smartphone app B4UFLY that is in limited Beta release. Once that is available, it should be a good resource.
Mapbox has a national map of drone restricted space. Its maps are also being used by other vendors. Mapbox is based on an open source database, so expect it to expand. Right now it just lists major airports, not seaplane bases, gliderports, or heliports. There is a cautionary tale on Wired which explains that there is a No Fly Zone over the nuclear lab at Lawrence Livermore patrolled by a 1 mile cannon, but that particular NFZ is not on any map. That will change, however, as people add unmapped areas to the open source database.
Airmap seems to be very complete, and currently if you register for a free account you can see maps, with selectable overlays for your rules, on you computer. This is the vendor 3DR is working with for its Solo app.
Also check with property owners if you fly over any land, and be aware of any state or local laws. The FAA release a fact sheet with guides for local authorities in an effort to prevent a ‘patchwork quilt’ of differing restrictions. Good for them! For example, they explained what might be pre-empted, and what would probably be within local power. Check it out.
It may be too early to give more information on this, but the 5 miles airport limit is not a hard and fast NFZ. The Rule is that when flown within 5 miles of an airport, the operator of the aircraft needs to provide the airport operator and the airport air traffic control tower with prior notice of the operation.
Drone Buddy is a free iPhone app. It shows no fly zones that seem similar to the Mapbox zones. Since it is currently free, check it out.