Apps like 'SkyDemon' and similar will graphically show you D/P/R zones as an overlay on the charts, and also alert you if you're flying close to them. Of-course this requires a subscription, and a iphone/android/ipad in the flight-deck with you.
Other than that, I suppose it would be good practice as a VFR pilot to have an up-to-date chart of the airspace you're flying in. Here in the UK, there listed with co-ordinates on the NATS website, along with operational hours, relevant freq. for information etc.