Hello John,
The FAA has published in PDF form a set of legends for VFR charts, IFR charts, and terminal procedures. The references are great, so we've elected to link to them.
We recommend customers download copies of these PDFs and keep them in iBooks or PDF reader app of choice: http://bit.ly/nK4622
To download to your iPad/iPhone, first install iBooks (free) from the App Store, then tap Safari and go to the above link. Then tap the link for the PDF version of the FAA Aeronautical Chart User's Guide. When the Guide appears, tap the Open in iBooks. Use the scroll bar along the bottom to move quickly through the documents.
Also, Airspace details are now an interactive feature in ForeFlight Mobile v4. Just tap and hold on the airspace on the VFR or IFR enroute charts, a box will pop up, tap All, and the first item(s) list will be the airspace details.
Also, be sure to set the Show Map Features to Tap-Hold in the ForeFlight Mobile Settings.
Give that a try and let us know if any other questions arise -- we're happy to help!
Stanley Hinson
ForeFlight Pilot Support
ForeFlight LLC