Avionics

AOPA's Garmin 430 Tutorial:  http://flash.aopa.org/asf/vfrgps/

GNS 430W Manual:  https://buy.garmin.com/shop/store/manual.jsp?product=010-00412-01&cID=194&pID=301

GNS 430 Manual: https://buy.garmin.com/shop/store/manual.jsp?product=010-00139-11&cID=169&pID=82

1978 C172N POH: http://www.askacfi.com/628/c172-poh.htm

Engine

The Whys and Hows of Engine Preheating: http://www.reiffpreheat.com/Article-Busch.htm

Zen and the Art of Engine Health: http://www.sacskyranch.com/zen.htm

Navigation

Tim's Navigation Simulator

Aircraft

Piper Cherokee Information Manual: 1976 Cherokee Information Manual

General

Find an Aviation Medical Examiner:  http://www.faa.gov/pilots/amelocator/