Mars is mapped to a degree, you can explore Mars on "Mars Trek".
MRO (Mars Reconnaissance Orbiter) is used to look for potential obstacles for the various rovers.
Mars Reconnaissance Orbiter is looking at small-scale features
In its survey of the red planet, the Mars Reconnaissance Orbiter is increasing tenfold the number of spots surveyed close-up. One of the orbiter's cameras is the largest ever flown on a planetary mission. Though previous cameras on other Mars orbiters could identify objects no smaller than a school bus, this camera can spot something as small as a dinner table. That capability has allowed the orbiter to identify obstacles such as large rocks that could jeopardize the safety of landers and rovers, including the Phoenix mission and Mars Science Laboratory mission. Its imaging spectrometer looks at small-scale areas about five times smaller than a football field, a scale perfect for identifying any hot springs or other small water features.
Still, the MRO's resolution is limited so the rovers take images and send them back to the planners for analysis.
The Lunar equivalent of the MRO is unimaginatively called the LRO. Its mission is to map the lunar surface and identify potential landing sites, find resources that could be used in a future, etc.
I think there are other spacecraft dedicated to mapping the Moon, the Indian Chandrayaan-1 comes to mind, but I don't know what else is currently there.
Here is a good article that describes what sites NASA is considering for the Mars 2020 rover.
Basically, the two main considerations are what's the scientific value of the site and given the engineering constraints, how much of the objectives can be achieved.
You probably want to consider elevation data - it seems the rovers we do send to Mars are meant to work on fairly flat surfaces. You can kind of see flatness on "Mars Trek" but there are also elevation maps.
Dust cover, verticle roughness and other datasets can be found here.
If the rover has solar panels you probably care about illumination data as well as some of the craters might be in permanent darkness.
The rover-friendliness of the potential landing site is just one factor, the scientific value of the site is usually given higher importance and the design of the rover is a compromise between science value and development cost.