How would you know if an airport has RVR capability? and what type of RVR readings it can provide, such as at the touchdown zone, midfield, or rollout.

For Jepps, back of the airport diagram.

Its on the back of the -9 airport diagram under additional runway information, it will say "RVR".

Same for the transmissometers, I look at the takeoff requirements. If it lists TDZ, MID and Rollout then it is has all three.

Also the AFD I would imagine.

edit: TheFly beat me to it.

The FAA RVR Monitoring Tool allows you to view live RVR from 48 different airports.