The U.S. government has a site for free downloading of airport and navigation information. Click here to download the airport/facility directory, terminal procedures (approach plates and airport diagrams) and other information. There are some problems with certain browsers but the FAA says they are working on the problem.
The same free information is not available for Canada (with the exception of airport diagrams for airports that have terminal procedures) because our government and Nav Canada consider this safety information as for sale only. As a measure to partially address this shortfall in safety information, COPA has our Places to Fly listing of airports and related services and local information. Places to Fly is not official data and pilots should always consult the official publications when flight planning.