Documentation

Update: Updated NASA Balloon Link
Documents  

HAPB-1

 Schematic, PCS Code, SCS Code
HAPB-2
 Schematic, Telemetry System
HAPB-3
 PCS Code, SCS Code, ReadEEPROM Code
  Modifing the CoolPix
  Making a Balloon Filling Rig
  Unmanned Free Balloon Regulations
Ground Tracking Stations
External Links  
  Balloon Supplier - Kaymont
  Flight Predictions - Near Space Ventures
  Parachutes - Rocketman
  Balloon Launchings - ARHAB
  Micro-Controllers - Parallax
  Electronics - Mouser
  APRS - OpenTracker
Updated
 NASA - Scientific Ballooning Program
  Federal Coordinator for Meteorology - Handbook No. 3
  Upper Air Soundings - UWYO Atmospheric Science
Just for Fun  
  Flash animation of HAPB-3 flight