VOR/ADF Navigation Simulator: A wonderful navigation aid trainer that allows the user to interpret the readings of RMI’s, VOR’s, and HSI’s and to see the effects of wind drift on air navigation. Written by Tim Carlson.
LiveATC: Listen to hundreds of live audio streams from air traffic control frequencies all over the world. I recommend IFR students listen and mentally phrase responses.
ATC Monitor: A fantastic controller’s-eye view of the northeast sector of Atlanta’s airspace complete with live audio and weather from Atlanta Approach and Tower.
Garmin GNS 400/500 Simulators: These really help to familiarize and reveal the full power of the Garmin 400 and 500 series.
Exams4Pilots: Free FAA written exam practice tests. They have everything from Sport Pilot to ATP, and every test in between, including the Flight Engineer test and various mechanic tests.
Learn to Fly by Max Trescott: This 37-page ebook discusses why one should learn to fly by featuring case studies of three pilots who learned to fly for different reasons: for pleasure, as a business tool, and as a career. It answers common questions such as “What will it cost to fly?” and “Is flying safe?” It also features a Learn to Fly checklist future pilots can use to plan each major step to earning a Private or Sport Pilot certificate. The ebook is downloadable for free with no strings attached (e.g. no need to register, give an email address or share any personal information).